Andy Galpin is a Professor of Kinesiology at California State University at Fullerton, where he studies muscle adaptation and applies his research to work with professional athletes. In this episode, Andy sets the foundation for the conversation by discussing the anatomy, microanatomy, and physiology of the muscle, including explaining what it actually means to undergo hypertrophy of the muscle. He then explains the difference between power, strength, speed, and hypertrophy and how those differences relate to what’s happening at the cellular level and the functional unit level. Additionally, he discusses energy sources for muscles, the importance of protein for muscle synthesis, the various types of muscle fibers, and the factors that determine one’s makeup of muscle fibers. Finally, Andy wraps the conversation with how he would design a program for an untrained person committed to adding muscle and functional strength for longevity.

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We discuss:

• Andy’s path to expertise in exercise [3:30];
• Contrasting strength, power, and force production and how they inform us about training for longevity [9:30];
• Muscle energetics: Fuels that provide energy to muscles, and the importance of protein [17:45];
• The structure and microanatomy of muscle, muscle fibers, and more [29:30];
• Energy demands of skeletal muscle compared to other tissues in the body [39:45];
• How a muscle contraction works and why it requires ATP [48:00];
• Muscle fibers: modulation between fiber types with movement and changes in fibers with training and aging [53:15];
• Andy’s study of twins demonstrating the difference in muscle fibers between a trained and untrained individual [1:02:30];
• Microanatomy of fast-twitch and slow-twitch muscle fibers [1:11:15];
• Factors that determine one’s makeup of muscle fibers, and how adaptable they are with training [1:22:15];
• Explaining hypertrophy and what happens at the cellular level when a muscle grows [1:30:00];
• How athletes quickly cut water weight and the rehydration process [1:37:30];
• Comparing different types of athletes [1:47:30];
• Training advice for a hypothetical client who’s untrained and wants to add muscle and functional strength for longevity [1:49:45];
• Changes in muscle and muscular function that occur with aging [1:53:45] ;
• Training plan for the hypothetical client [1:59:30];
• What drives muscle hypertrophy? [2:12:15];
• How to properly incorporate isometric exercises into a workout [2:19:00];
• Additional training tips: movement patterns, how to finish a workout, and more [2:25:45];
• Ways to incorporate high heart rate exercise into a workout plan [2:28:45]; and
• More

Show Notes

*Notes from intro :

• Andy Galpin is a professor of Kinesiology at California State University, Fullerton where his biochemistry and molecular exercise physiology lab researches the acute responses of chronic adaptations of skeletal muscle to high intensity power or force and fatiguing exercise
• Andy’s research spans adaptations from whole muscle to cellular level changes
• He has applied his work to professional athletes for about 15 years
• In this episode, we focus our conversation specifically around one of the four pillars of exercise‒ strength
• We focus a lot of the conversation around muscle
• In the beginning of this episode we talk pretty technically about the anatomy, microanatomy, and physiology of the muscle This is important to really understand some of the details This is a subject matter that Peter talks about a lot A lot of podcasters talk about this alot
• We discuss the simple question‒ what does it mean to undergo hypertrophy? What does it mean for a muscle to get bigger? What exactly is getting bigger?
• What is the difference between power, strength, speed, and hypertrophy? How do those differences phenotypically relate to what’s happening at the cellular level or at the functional unit level?
• We talk about muscles and their energy sources
• We talk about the importance of protein for muscle synthesis
• We talk about the various types of muscle fibers Peter learned more about this topic than anything else they spoke about
• We end the conversation looking at a case study of how Andy would create a program for an untrained person who had just started doing a few hours of cardio (per week) and wanted to spend three days a week building strength With a focus on building strength for longevity We did this because that approach was so popular in some of our previous podcasts Listeners really like hearing how you apply some of this high fluid science to your life

• One final point, Peter goes into these podcasts with a long list of topics he wants to explore, and sometimes he doesn’t get close to it That was certainly the case here; they barely scratched the surface of what Peter wanted to cover This episode will be part one of two

• This is important to really understand some of the details

• This is a subject matter that Peter talks about a lot

• A lot of podcasters talk about this alot

• What does it mean for a muscle to get bigger?

• What exactly is getting bigger?

• How do those differences phenotypically relate to what’s happening at the cellular level or at the functional unit level?

• Peter learned more about this topic than anything else they spoke about

• With a focus on building strength for longevity

• We did this because that approach was so popular in some of our previous podcasts

• Listeners really like hearing how you apply some of this high fluid science to your life

• That was certainly the case here; they barely scratched the surface of what Peter wanted to cover

• This episode will be part one of two

Andy’s path to expertise in exercise [3:30]

• Peter has wanted to speak with Andy for quite some time and listeners to this podcast know how much of an emphasis he places on exercise
• Peter has said it many times before, “ There’s really no more potent tool to improve longevity (meaning extending the length of life and improving the quality of life) than exercise. And that includes nutrition, and that includes sleep, and that includes the entire pharmacopeia of medication, supplements, drugs, hormones, etc. ”

Peter divides exercise into different pillars

• 1) Strength
• 2) Stability

• 3) & 4) Cardiorespiratory fitness (further subdivided by the metabolic state and energy state) Zone 2 Zone 5

• Zone 2

• Zone 5

• Today we’re going to focus on strength and things that stem from that (like hypertrophy) which are of huge interest to people

Andy’s background in exercise

• Andy begins by stating a conflict of interest, “ I’m an exercise scientist… I actually assign strength training ” He is biased to giving more credit to exercise for longevity and wellness

• Andy grew up in a very small town in southwest Washington

• He is biased to giving more credit to exercise for longevity and wellness

College

• He played everything in high school‒ football, basketball, baseball, track and field
• He went to a small school in Oregon where he played college football and got his undergraduate degree in exercise science
• After that he worked in Arizona training professional athletes
• He went back and got his Master’s degree in human movement sciences, which is just another fancy way of saying kinesiology or exercise science
• Then he got his PhD in human bioenergetics

In 2011 he came out to California and has been working at Cal State Fullerton ever since

• For a while now, he’s been the director for the Center for Sport Performance there
• He also runs a Biochemistry and Molecular Exercise Physiology lab at Cal State Fullerton

In terms of sports, Andy played college football and then training professional athletes

• He started competing in weightlifting (which colloquially is Olympic weightlifting) and then combat sports a while after that
• He has continued to work with athletes in just about every sport while running his lab (doing research) over the last 10 years
• His research and interests come back to the same point‒ the details for training and recovery are important for performance
• He was a decent athlete and felt like he was in the perfect spot because he wasn’t so good that these details didn’t matter The details of effective training and recovery mattered This was the difference between him being a starter and not He was good enough to know where he got rewarded If you’re not good enough, then it doesn’t matter what you do because you’re not going to play at the next level He was totally obsessed with giving himself every advantage He wanted to go All Pro (but that didn’t happen) He knew he was never going to be a professional level caliber or even Division I, but he wanted to play college football This is where his passion came from
• He grew up in a small town, a very working class place where losing was always fine There was always someone better than you But losing because you didn’t prepare was totally unacceptable
• Most of the kids he grew up with worked before school (on farms or cleaning stalls)
• His parents worked in construction
• The whole idea of fending for yourself and getting what you earn was something he grew up with

• He moved into sports and academia with the expectation that, “ If you want a chance, it’s on you and nobody else. And so do the work or don’t do the work .” This pushed him to get where he is

• The details of effective training and recovery mattered

• This was the difference between him being a starter and not
• He was good enough to know where he got rewarded If you’re not good enough, then it doesn’t matter what you do because you’re not going to play at the next level
• He was totally obsessed with giving himself every advantage
• He wanted to go All Pro (but that didn’t happen)
• He knew he was never going to be a professional level caliber or even Division I, but he wanted to play college football

• This is where his passion came from

• If you’re not good enough, then it doesn’t matter what you do because you’re not going to play at the next level

• There was always someone better than you

• But losing because you didn’t prepare was totally unacceptable

• This pushed him to get where he is

After his own athletic career…

• He worked with athletes who wanted to pursue tremendous goals like go to the Olympics

• He also found that some sports (like women’s wrestling) have no funds; no one is going to help them Andy became very interested in these people because he saw that he could help them a lot, and no one else cares about them This is what motivated him to get his Master’s and PhD He wanted to learn more and find all the all the answers he can

• Andy became very interested in these people because he saw that he could help them a lot, and no one else cares about them

• This is what motivated him to get his Master’s and PhD He wanted to learn more and find all the all the answers he can

• He wanted to learn more and find all the all the answers he can

Contrasting strength, power, and force production and how they inform us about training for longevity [9:30]

How does Olympic lifting contrast with powerlifting?

• Layne Norton has been on the podcast several times [see the Selected Links section at the end]; he’s a very successful powerlifter
• In powerlifting, you get three lifts and it’s all about your total in those three lifts

“ I’ll preface the question for the listener by saying, even if you never plan to powerlift or Olympic lift, this is going to be germane to our discussion ”‒ Peter Attia

• Andy recently published the most in-depth analysis of muscle composition of Olympic weightlifters

Comparing/contrasting powerlifting, Olympic weightlifting, and Strongman competitions to help define strength, force production, and power

• When you think about powerlifting, force production is a one-rep max (in the case of lifting) It’s the most amount of weight you can lift one time (not how many times you can do it) Not how fast you can do it
• In the sport of powerlifting (like what Layne does), it is three exercises‒ the deadlift, bench and the squat It’s how much weight can you lift one time You get a couple of tries at it, but that’s effectively what it is
• Powerlifting is an expression of pure strength , not power (because the speed component is very poor)
• It doesn’t matter how long the deadlift takes This can be confusing because the sport is called powerlifting, despite the fact that it is not a power exercise, nor is it determined by power
• When you move over to Olympic weightlifting , it’s the same basic idea There are now two lifts instead of three‒ one lift being called the snatch and the other one’s called the clean and jerk It’s called the clean and jerk because it has two parts‒ you clean it to your chest and then you jerk it over your head (but it’s still considered one lift) Whoever can lift the most amount one time is the winner (one-rep max) There’s no repetition method to it The difference is this is now more an expression of power because although it’s all about one-rep max, it’s difficult to lift something over your head as high as possible slowly (there’s a speed component) It is an expression of tremendous strength, but there’s this velocity component to it When you multiply force by velocity, now you’ve got power , and so technically the Olympic weightlifters are significantly more powerful than a powerlifter (despite the confusing name)
• This gets worse when we start roping in things like strongman You would think that must be the biggest expression of strength, where in fact it’s not because strongman is contested over multiple repetitions It is an expression of very, very high strength repeated several times It’s not technically a true one-rep max

• Andy points out about powerlifting, weightlifting, and strongman, “ None of those three things are actually explaining what they do correctly ”

• It’s the most amount of weight you can lift one time (not how many times you can do it)

• Not how fast you can do it

• It’s how much weight can you lift one time

• You get a couple of tries at it, but that’s effectively what it is

• This can be confusing because the sport is called powerlifting, despite the fact that it is not a power exercise, nor is it determined by power

• There are now two lifts instead of three‒ one lift being called the snatch and the other one’s called the clean and jerk It’s called the clean and jerk because it has two parts‒ you clean it to your chest and then you jerk it over your head (but it’s still considered one lift)

• Whoever can lift the most amount one time is the winner (one-rep max) There’s no repetition method to it
• The difference is this is now more an expression of power because although it’s all about one-rep max, it’s difficult to lift something over your head as high as possible slowly (there’s a speed component)
• It is an expression of tremendous strength, but there’s this velocity component to it

• When you multiply force by velocity, now you’ve got power , and so technically the Olympic weightlifters are significantly more powerful than a powerlifter (despite the confusing name)

• It’s called the clean and jerk because it has two parts‒ you clean it to your chest and then you jerk it over your head (but it’s still considered one lift)

• There’s no repetition method to it

• You would think that must be the biggest expression of strength, where in fact it’s not because strongman is contested over multiple repetitions

• It is an expression of very, very high strength repeated several times
• It’s not technically a true one-rep max

This is important because it also explains training adaptations

• It’s a perfect way to outline to understand what’s happening
• If you train like a powerlifter , that probably represents the best way to get truly strong Powerlifting is very controlled‒ very specific foot position and hand position You’re minimizing range of motion intentionally because you want to minimize work, (work being force times distance), and if the name of the game is who can create the most force If you can minimize the distance you’re going to win, and that’s why they take those funny positions
• If you train like a weightlifter, it represents the best way to get powerful With Olympic weightlifting, more coordination required because you’re going to take a weight from the ground, throw it over your head and catch it over your head in a full squat This requires things like balance and proprioception and eccentric catching

• If you train like a strongman , it represents a fantastic way to get very, very strong in more life-functional movements Walking, carrying, lifting objects and doing it probably multiple times

• Powerlifting is very controlled‒ very specific foot position and hand position

• You’re minimizing range of motion intentionally because you want to minimize work, (work being force times distance), and if the name of the game is who can create the most force If you can minimize the distance you’re going to win, and that’s why they take those funny positions

• If you can minimize the distance you’re going to win, and that’s why they take those funny positions

• With Olympic weightlifting, more coordination required because you’re going to take a weight from the ground, throw it over your head and catch it over your head in a full squat

• This requires things like balance and proprioception and eccentric catching

• Walking, carrying, lifting objects and doing it probably multiple times

How does hypertrophy fit within this trio?

• Hypertrophy would be more of your bodybuilding

• Which Layne has also done Holly was just on the podcast and whether you call it bodybuilding or general physique, she can smash with physique

• Bodybuilding is simply improving generally leanness and total muscle mass There’s a component of symmetry and shape, things like that that don’t really matter for this conversation Now you’re talking about optimized muscle size as well as leanness with no consideration for function It doesn’t matter if you’re strong or fast or athletic or any of those thing

• Andy remarks, “ It’s so interesting that you started the conversation like this because this is day one of my Strength and Conditioning course ” He spends the first week going over these different categories of sport because it outlines exactly how to train

• Which Layne has also done

• Holly was just on the podcast and whether you call it bodybuilding or general physique, she can smash with physique

• There’s a component of symmetry and shape, things like that that don’t really matter for this conversation

• Now you’re talking about optimized muscle size as well as leanness with no consideration for function

• It doesn’t matter if you’re strong or fast or athletic or any of those thing

• He spends the first week going over these different categories of sport because it outlines exactly how to train

Andy adds two more training categories

• 1 – Competitive circuit training sports (like CrossFit ) These people are very strong , they have a lot of muscle, but they’re not nearly as strong as powerlifters or the World’s Strongest Men, but they do a lot more repetitions A World’s Strongest Man is going to win an event doing something like 5-15 repetitions
• In CrossFit, you might have to do 90 reps in a given workout It’s way higher up that scale of number of repetitions Of course, they do some that are one-repetition They do a lot of different functional movements and a lot of workouts repeated in the same day It’s a very different test of recovery over three or four days of just brutal onslaught, where you’re asked to do things in a lot of different areas and a lot of different energy systems and movement patterns etc. CrossFit is a really interesting test of total physical fitness

• 2 – Track and field is the truest expression of velocity These are the people who are going to be the best at getting truly fast

• These people are very strong , they have a lot of muscle, but they’re not nearly as strong as powerlifters or the World’s Strongest Men, but they do a lot more repetitions A World’s Strongest Man is going to win an event doing something like 5-15 repetitions

• A World’s Strongest Man is going to win an event doing something like 5-15 repetitions

• It’s way higher up that scale of number of repetitions

• Of course, they do some that are one-repetition
• They do a lot of different functional movements and a lot of workouts repeated in the same day
• It’s a very different test of recovery over three or four days of just brutal onslaught, where you’re asked to do things in a lot of different areas and a lot of different energy systems and movement patterns etc.

• CrossFit is a really interesting test of total physical fitness

• These are the people who are going to be the best at getting truly fast

What do you need to have as a functional human being for lifespan longevity or sport?

• Think of this as a spectrum, and consider the questions‒ How do I get to be absolutely the fastest? How do I get the most powerful? How do I get strong? How do I add muscle size/loose body fat? How do I improve my muscular endurance? How do I improve my cardiovascular and metabolic endurance?

• This is now occupied in all of those sports, and so we can look at them as a model for training and saying, “ The best in the world at getting stronger have been doing this .” We have different models of that, and that is a nice foundation for all training

• How do I get to be absolutely the fastest?

• How do I get the most powerful?
• How do I get strong?
• How do I add muscle size/loose body fat?
• How do I improve my muscular endurance?

• How do I improve my cardiovascular and metabolic endurance?

• We have different models of that, and that is a nice foundation for all training

Muscle energetics: Fuels that provide energy to muscles, and the importance of protein [17:45]

What is a muscle? What is the functional unit? How does it generate force? What are the metabolic demands? What makes these cells that are so ubiquitous in our body different from, say, the cells in our liver, the cells in our gut, the cells in our brain? What are these cells that we almost take for granted sometimes?

What is the biggest organ in your body?

• Most people generally say the skin

• As an exercise scientist and muscle physiologist, Andy gives all the credit to muscle He doesn’t care about the organs that support muscles‒ the heart, the liver, the lungs, or his “worst enemy”, the nervous system Andy is biased towards muscle

• He doesn’t care about the organs that support muscles‒ the heart, the liver, the lungs, or his “worst enemy”, the nervous system

• Andy is biased towards muscle

Muscle is going to be the largest organ in your body. It’s doing everything from supporting function, locomotion, to being your biggest reserve for amino acids, and your biggest dump for regulating metabolism

“ I could go on and on and on about the physiological, the practical, the general health benefits of skeletal muscle ”‒ Andy Galpin

• Peter hones in on this idea of muscle as a storage depot for amino acids Layne did a great job talking about this in the podcast , explaining that we are constantly breaking down and adding new There’s a pool of amino acids that’s turning over, and it’s very difficult to study them from a flux perspective If you’re working out, it’s a plausible scenario that proteins are being broken down and amino acids released These may not be resynthesized back into that same piece of skeletal muscle They may be used for another application (Andy thinks this is guaranteed to happen)

• Layne did a great job talking about this in the podcast , explaining that we are constantly breaking down and adding new

• There’s a pool of amino acids that’s turning over, and it’s very difficult to study them from a flux perspective

• If you’re working out, it’s a plausible scenario that proteins are being broken down and amino acids released These may not be resynthesized back into that same piece of skeletal muscle They may be used for another application (Andy thinks this is guaranteed to happen)

• These may not be resynthesized back into that same piece of skeletal muscle

• They may be used for another application (Andy thinks this is guaranteed to happen)

Andy uses an analogy to explain energetics

• Andy shot a cheesy video 10 years ago in his backyard about the basics of energy using the analogy of a campfire
• If you’re a outdoorsman and you are going to be out camping, you may need to create a fire
• 1 – The first option is to use a match ‒ it’s going to give you instantaneous energy (the fire) but it only lasts a few seconds If you need energy right now, this is where you start In terms of your tissue, this is going to be ATP and your phosphocreatine energy system The stoichiometry is one to one, you break down one phosphocreatine to get one mole of ATP It’s generally loaded up on the myosin head or close to it so it can contract tissue (we’ll come back to actin and myosin)
• 2 – Now if you were a little more forward thinking, you would use the match to light a newspaper Paper would provide a fairly quick light, not as fast as a match, but it would give you a few minutes of energy (conceptually) The paper here is carbohydrates Carbohydrate is stored both in the cell as well as outside, but in the cell it’s going to give you a lot more energy You’re going to get a couple of moles of ATP per molecule of carbohydrate So carbohydrate is better than phosphocreatine, but it’s splitting hairs When carbohydrates get low, you can pull glucose out of the blood In the tissue carbohydrates are called glycogen Glycogen is also stored in the liver; it functions as a backup storage system for glucose to help you regulate blood glucose Blood glucose is one of the four things your body will regulate over almost anything else (the others are pH, blood pressure, and electrolyte concentrations); these need to be stable

• 3 – Next in the analogy for fuel to burn is a piece of wood Lighting firewood in the wild is very difficult to do; it doesn’t happen in seconds, but it’s going to give you exponentially longer burn time (hours) Think about that as fat If you know a little bit about the chemistry of fat versus carbohydrate, they’re both big long chains of carbon (just like a paper is actually made of wood) You get a small, six carbon chain from glucose You can get any number of lengths of chains of fat, such as a 18 carbon fatty acid chain You can put three of those on a backbone of glycerol and you’ve gotten yourself 50 carbon molecules per triglyceride or something like that The stoichiometry gets better here You’re going to get something like three or 400 ATP per molecule of fat, and that’s where things get actually better The fat is actually coming mostly from outside of the muscle So, energy from fat mobilization comes throughout the body somewhat evenly Glucose comes mostly from inside the muscle itself, and then a little bit from the backup supplies if it gets low Phosphocreatine comes directly from the muscle

• If you need energy right now, this is where you start

• In terms of your tissue, this is going to be ATP and your phosphocreatine energy system

• The stoichiometry is one to one, you break down one phosphocreatine to get one mole of ATP It’s generally loaded up on the myosin head or close to it so it can contract tissue (we’ll come back to actin and myosin)

• It’s generally loaded up on the myosin head or close to it so it can contract tissue (we’ll come back to actin and myosin)

• Paper would provide a fairly quick light, not as fast as a match, but it would give you a few minutes of energy (conceptually)

• The paper here is carbohydrates
• Carbohydrate is stored both in the cell as well as outside, but in the cell it’s going to give you a lot more energy You’re going to get a couple of moles of ATP per molecule of carbohydrate
• So carbohydrate is better than phosphocreatine, but it’s splitting hairs
• When carbohydrates get low, you can pull glucose out of the blood
• In the tissue carbohydrates are called glycogen
• Glycogen is also stored in the liver; it functions as a backup storage system for glucose to help you regulate blood glucose

• Blood glucose is one of the four things your body will regulate over almost anything else (the others are pH, blood pressure, and electrolyte concentrations); these need to be stable

• You’re going to get a couple of moles of ATP per molecule of carbohydrate

• Lighting firewood in the wild is very difficult to do; it doesn’t happen in seconds, but it’s going to give you exponentially longer burn time (hours)

• Think about that as fat
• If you know a little bit about the chemistry of fat versus carbohydrate, they’re both big long chains of carbon (just like a paper is actually made of wood)
• You get a small, six carbon chain from glucose
• You can get any number of lengths of chains of fat, such as a 18 carbon fatty acid chain You can put three of those on a backbone of glycerol and you’ve gotten yourself 50 carbon molecules per triglyceride or something like that The stoichiometry gets better here You’re going to get something like three or 400 ATP per molecule of fat, and that’s where things get actually better
• The fat is actually coming mostly from outside of the muscle
• So, energy from fat mobilization comes throughout the body somewhat evenly
• Glucose comes mostly from inside the muscle itself, and then a little bit from the backup supplies if it gets low

• Phosphocreatine comes directly from the muscle

• You can put three of those on a backbone of glycerol and you’ve gotten yourself 50 carbon molecules per triglyceride or something like that

• The stoichiometry gets better here
• You’re going to get something like three or 400 ATP per molecule of fat, and that’s where things get actually better

But how does protein fit into this analogy?

• Protein in this analogy would be functioning more like a piece of metal

• If you had metal in the woods and you needed a fire and you had absolutely nothing else, you can in theory melt metal with a fire But it is a very, very low end proposition If you absolutely have to do it, you can do it to survive But if that’s your fueling strategy, you’re in a big, big problem because you’re going to run out of metal very quickly in the woods It’s mostly there for you to reconstruct new tools; it’s meant to be broken back down and recreated in different forms

• But it is a very, very low end proposition

• If you absolutely have to do it, you can do it to survive
• But if that’s your fueling strategy, you’re in a big, big problem because you’re going to run out of metal very quickly in the woods
• It’s mostly there for you to reconstruct new tools; it’s meant to be broken back down and recreated in different forms

Andy’s summary

• What we’re looking at is the ability to play back and forth with carbohydrate and fat as a different fuel system

• The point of protein in tissue is its function for skeletal muscle; it is not fuel We need it for our immune system and other functions

• We need it for our immune system and other functions

The importance of protein in your diet

• If your body is choosing between keeping a 24-inch biceps or clearing up something immunologically, it’s going to go toward the latter
• Let’s say you spend a lot of time on your biceps and they get really, really big, but you don’t train your calves and your protein intake is insufficient You will start redistributing protein from the calf to the bicep to enable that growth You think you’re getting bigger, but you’re really just taking it from other places if protein intake itself is not sufficient

• This is why people are so diligent about protein intake and why this has become such a big deal

• You will start redistributing protein from the calf to the bicep to enable that growth

• You think you’re getting bigger, but you’re really just taking it from other places if protein intake itself is not sufficient

Protein is the raw material you really can’t get anywhere else

• You can get carbohydrates and fat in a lot of ways
• You can’t make muscle without protein
• When you start losing muscle, you enter a whole cascade of problems with physical performance

More muscle means a longer life

• When you look at people across lifetimes and divide them by amount of mass it’s clear they live longer
• Note that strength is the better determinant for longevity than mass, however, mass it very easy to identify and it’s correlated to strength
• It’s easier to measure muscle mass than strength; all you need to do is put somebody in a DEXA and you can figure out their appendicular lean mass index (ALMI)

“ There’s no ambiguity about the fact that more muscle means a longer life. It’s as clear as high VO 2 max means a longer life. ”‒ Peter Attia

The structure and microanatomy of muscle, muscle fibers, and more [29:30]

Creating movement requires three core functions

• 1 – It begins with a direction or signal coming from your nervous system, telling the muscle what to do It doesn’t matter if this is central or peripheral, autonomic or controlled somatic action A nerve has to go into a muscle fiber and tell that muscle fiber to contract
• 2 – Muscle fiber contraction This doesn’t cause movement Muscles are not attached to bone Muscle fibers are surrounded by connective tissue, and all that connective tissue is bundled together in a package Imagine buying a bunch of strips of bacon from the butcher all wrapped up in saran wrap together; that’s what a muscle looks like If you pulled on one piece of bacon, you’d notice the whole package moves

• 3 – You’re transferring force from muscle through connective tissue That connective tissue comes together into a tendon, and that tendon then attaches to bone

• It doesn’t matter if this is central or peripheral, autonomic or controlled somatic action

• A nerve has to go into a muscle fiber and tell that muscle fiber to contract

• This doesn’t cause movement

• Muscles are not attached to bone

• Muscle fibers are surrounded by connective tissue, and all that connective tissue is bundled together in a package Imagine buying a bunch of strips of bacon from the butcher all wrapped up in saran wrap together; that’s what a muscle looks like If you pulled on one piece of bacon, you’d notice the whole package moves

• Imagine buying a bunch of strips of bacon from the butcher all wrapped up in saran wrap together; that’s what a muscle looks like

• If you pulled on one piece of bacon, you’d notice the whole package moves

• That connective tissue comes together into a tendon, and that tendon then attaches to bone

To summarize what generates human movement‒ a signal causes a muscle to contract, and that muscle makes connective tissue pull on a bone

• Andy will leave step 1 (neuroscience) to other people A nerve will come down and attach and innervate a whole host of muscle fibers
• It’s difficult to understand what’s happening with connective tissue; it’s not very plastic
• Muscle is tremendously plastic, meaning it adapts and changes very rapidly in response to a lot of things

• Connective tissue doesn’t have a blood flow supply, it doesn’t have an energetic demand

• A nerve will come down and attach and innervate a whole host of muscle fibers

“ The core of the issue of adaptations, whether they are pro or negative, is going to be in skeletal muscle ”‒ Andy Galpin

Special properties of skeletal muscle

• Skeletal muscle fibers are some of the largest cells in all of biology (by diameter)
• In humans, they’re tremendous
• What makes humans special is that our muscle fibers are what’s called multinucleated It’s very uncommon in nature to see cells that have more than one nucleus The nucleus is the control center of the cell; that’s what holds your DNA and tells you when to replicate proteins to grow, shrink, die, repair

• Skeletal muscle has thousands of nuclei per cell; it can be extraordinarily large (see the video below) A single muscle fiber from a human is large enough to pick up with tweezers; you can see the whole muscle cell with your naked eye They can be very, very long (several inches in length)

• It’s very uncommon in nature to see cells that have more than one nucleus

• The nucleus is the control center of the cell; that’s what holds your DNA and tells you when to replicate proteins to grow, shrink, die, repair

• A single muscle fiber from a human is large enough to pick up with tweezers; you can see the whole muscle cell with your naked eye

• They can be very, very long (several inches in length)

Figure 1. A single muscle fiber is a large, multinucleated cell. Image credit: Andy Galpin CSUF

How do you define a muscle cell?

• Normally, we define a cell by the constitutive elements of a cell membrane, a single nucleus, etc.
• For a muscle cell (aka muscle fiber ), we are looking at a longer tube as opposed to a sphere It’s still circular like any other cell, but it’s a very long tube

• Think of a muscle cell like a ponytail and compare to the figure below A ponytail is made up of a bunch of individual hairs that are bound together and form a long tube This is what a skeletal muscle system looks like

• It’s still circular like any other cell, but it’s a very long tube

• A ponytail is made up of a bunch of individual hairs that are bound together and form a long tube

• This is what a skeletal muscle system looks like

Figure 2. Muscle fiber organization . Image credit: OpenStax Anatomy and Physiology .

• Skeletal muscle is quite different from cardiac muscle Cardiac muscle cells are more rectangular Skeletal muscle fibers are very long and narrow but still circular

• Skeletal muscle cells still have a cell membrane, more of the organelles are the same as any other cell, but they have a bunch of nuclei

• Cardiac muscle cells are more rectangular

• Skeletal muscle fibers are very long and narrow but still circular

What is the typical length of a skeletal muscle cell?

• For skeletal muscle, structure is function so you can’t give a typical length
• Contrast this with cardiac tissue, the ultimate slow-twitch fiber Cardiac tissue is even more slow-twitch than skeletal tissue and it tends to be fairly uniform
• If you look at your sartorius (the muscle that goes from the pointy part of the front of your hip down to the inside middle of your knee), theoretically those fibers (a single cell) could run that whole distance
• If you consider an ocular muscle (in the eye), it’s going to be extremely small in length
• A muscle cell in your fingers are also going to be very, very short

• There is not classic range; a skeletal muscle cell could be anywhere from mm to inches in length

• Cardiac tissue is even more slow-twitch than skeletal tissue and it tends to be fairly uniform

Presumably the reason these cells have multiple nuclei is to decentralize the actions of cellular construction

• The DNA is used to make RNA in the proximity of the nucleus; from this proteins are made
• Even a 1 cm long cell would be enormous, and you simply couldn’t make all of that work with one nucleus

Do these nuclei in a single muscle cell act independently? Where is the central command?

• The nucleation question is very interesting and amazingly adaptive

• Andy has shown in his lab that a lot of professional athletes have more nuclei per volume He posit’s this may be why they can adapt so well With more nuclei, they can handle the volume of exercise

• He posit’s this may be why they can adapt so well

• With more nuclei, they can handle the volume of exercise

How much is the number of nuclei per muscle cell genetic and how much is adaptation to training?

• Andy thinks both are important
• Numerous lifestyle factors influence this

• It’s not just the number of nuclei that matters; the shape matters There are spheres, ovals, etc

• There are spheres, ovals, etc

“ [For nuclei] It looks like the shape determines the function; the location determines the function. ”‒ Andy Galpin

• For example, there are subtypes of nuclei that surround the mitochondria and are very specific to mitochondria repair
• There are other subtypes of nuclei that are more specific to jobs in the periphery of the cell, responsive to the cell membrane and injury
• This is a very recent understanding and is probably why some folks recover or respond to injury more than others They may simply have more of a subtype of nuclei
• What’s challenging about addressing the question of nature versus nurture is the difficulty with measurement fidelity The tech is moving quickly; every couple years microscopes get better and we realize that the work of the three previous years are now invalidated
• In the area of cell growth ( hypertrophy ), there is tremendous confusion about the role of these nuclei in growth
• We used to think about mononuclear domain limitation ‒ the idea that the cell would only grow in diameter to the extent to which the nuclei could control it In order to gain more growth, you have to get more satellite cells to come in and add nuclei Then when you de-train, that cell reduces in diameter, but you preserve the additional nuclei This is why retraining is easier than training the first time This is the old adage of muscle memory
• Now it looks like this mechanism (of mononuclear domain limitation) is not correct; certainly it remains to be determined

• Peter notes that this question lends itself to a longitudinal study In an ideal world you would take young, pliable athletes in their teens and study them over time under different training demands The dream scenario is to study identical twins (we’ll come back to this)

• They may simply have more of a subtype of nuclei

• The tech is moving quickly; every couple years microscopes get better and we realize that the work of the three previous years are now invalidated

• In order to gain more growth, you have to get more satellite cells to come in and add nuclei

• Then when you de-train, that cell reduces in diameter, but you preserve the additional nuclei This is why retraining is easier than training the first time This is the old adage of muscle memory

• This is why retraining is easier than training the first time

• This is the old adage of muscle memory

• In an ideal world you would take young, pliable athletes in their teens and study them over time under different training demands

• The dream scenario is to study identical twins (we’ll come back to this)

Energy demands of skeletal muscle compared to other tissues in the body [39:45]

How hungry are muscle cells for energy?

• The liver is an amazing organ, Peter points out there is not extracorporeal support for the liver because we simply can’t replicate its complexity Extracorporeal simply means outside the body For example, dialysis is extracorporeal support for the kidney A VAD or an ECMO is extracorporeal support for the heart or heart and lungs combined A ventilator is extracorporeal support for lungs If a patient tragically overdoses on Tylenol in an attempt to take their life and they reach a point of irreversibly damaging the liver, you can’t put them on liver support until they get a transplant
• The liver controls glucose homeostasis with an amazing level of precision
• The liver is not a metabolically greedy organ; on its own it doesn’t consume much energy
• In contrast, the brain is a very complex organ and incredibly metabolically greedy Which is probably why we need the liver to support the brain Without the liver being so good at maintaining glucose homeostasis, our brain would’ve either needed an adaptation strategy away from glucose or we wouldn’t have brains as large as we do
• Peter asks, “ Where does the muscle fit into this hierarchy? Is the muscle a high maintenance organ? ”
• Andy compares the liver to a professional fighter, where you can beat it up a lot
• Kidneys don’t have this sustainability

• Andy also loves the liver, because it’s the closest thing in the body to skeletal muscle in terms of its ability to respond and change

• Extracorporeal simply means outside the body

• For example, dialysis is extracorporeal support for the kidney
• A VAD or an ECMO is extracorporeal support for the heart or heart and lungs combined
• A ventilator is extracorporeal support for lungs

• If a patient tragically overdoses on Tylenol in an attempt to take their life and they reach a point of irreversibly damaging the liver, you can’t put them on liver support until they get a transplant

• Which is probably why we need the liver to support the brain

• Without the liver being so good at maintaining glucose homeostasis, our brain would’ve either needed an adaptation strategy away from glucose or we wouldn’t have brains as large as we do

Story about liver transplants from Peter’s residency

• In his residency, Peter was involved with a number of live donor liver transplants This is an operation when an individual would donate a third to half of their liver to another person who was a really good HLA match
• What was interesting was the speed with which that portion of their liver would regenerate
• If you didn’t anticipate that growth with doses of intravenous phosphorus, they would have an enormous metabolic crisis There is no amount of food you could give this person to allow them to have enough phosphate backbone for the DNA and RNA and protein synthesis that was going on to reproduce their liver You had to give them IV phosphorus nonstop
• They could regenerate a third of their liver in two weeks (simply staggering) The caveat is, this only works when the architecture of the liver is preserved Once you cross into the path of cirrhosis and inflammation, it’s over Unfortunately, people with post- NAFLD , NASH, alcoholic liver disease , they have gotten to a point where their liver no longer has that capacity to regenerate
• When Andy does his single fiber experiments with skeletal muscle, you have to use a permanent bath of phosphorus
• Andy notes about the liver, “ You can mess up for a long time, but if you do take action before you hit that level… you can get a lot of regeneration/ recovery .”
• The kidneys are different; they are so sensitive to blood pressure and the damage of high glucose
• The lungs are sensitive to smoking and things like that
• Peter thinks the liver is an unsung hero of the body
• Andy agrees, it’s the thing that keeps you from bonking during endurance sports

• When the liver is finished, it doesn’t matter how much mental strength you have, you are going down If you watch any sports, someone gets hit in the liver and instantaneously, they’re crippled Peter asks, “ Isn’t that what happened to Oscar de la Hoya against Bernard Hopkins? ” Andy doesn’t remember, but he works a lot with UFC fighters, and he’s seen just the tip of a toe clip the liver and world champions get locked up and fall to the ground The liver does not like to be aggravated like that, but it will handle a beating for the most part

• This is an operation when an individual would donate a third to half of their liver to another person who was a really good HLA match

• There is no amount of food you could give this person to allow them to have enough phosphate backbone for the DNA and RNA and protein synthesis that was going on to reproduce their liver

• You had to give them IV phosphorus nonstop

• The caveat is, this only works when the architecture of the liver is preserved

• Once you cross into the path of cirrhosis and inflammation, it’s over

• Unfortunately, people with post- NAFLD , NASH, alcoholic liver disease , they have gotten to a point where their liver no longer has that capacity to regenerate

• If you watch any sports, someone gets hit in the liver and instantaneously, they’re crippled

• Peter asks, “ Isn’t that what happened to Oscar de la Hoya against Bernard Hopkins? ”
• Andy doesn’t remember, but he works a lot with UFC fighters, and he’s seen just the tip of a toe clip the liver and world champions get locked up and fall to the ground
• The liver does not like to be aggravated like that, but it will handle a beating for the most part

Back to the question of the energy demands of the muscle

• The muscle is tremendously responsive to everything you’re doing
• People will say that if you add more muscle mass, that’s going to elevate your basal metabolic rate so you’ll burn more calories just sitting there That is true, but it’s not to a level that you actually think It’s probably something like 30 calories per pound of added muscle People tend to think their basal metabolic rate is going to go from 1500 calories a day to 2,500 because they put on five pounds of muscle Andy adds, “ That’s way outside the realm of what’s going to happen ”

• There are many reasons you probably want to put some muscle on, but the metabolic boost is probably not one of them

• That is true, but it’s not to a level that you actually think

• It’s probably something like 30 calories per pound of added muscle

• People tend to think their basal metabolic rate is going to go from 1500 calories a day to 2,500 because they put on five pounds of muscle Andy adds, “ That’s way outside the realm of what’s going to happen ”

• Andy adds, “ That’s way outside the realm of what’s going to happen ”

In terms energetic demands, skeletal muscle is pretty lazy

• Skeletal muscle wants to be as efficient as possible
• Think about the functionality of physiology, you want your brain running full course as often as possible
• Skeletal muscle is a backup system; it’s there when you need something done to elevate your function Otherwise it’s in rest mode
• If you need it, muscle will jump into action
• If you have an energetic NEAT (non-exercise activity thermogenesis) to burn 200 calories, your foot will start tapping
• NEAT is non-exercise energy, burning energy that’s not physical activity or exercise or the energy needed to survive (breathe, digest, etc.) NEAT accounts for about 10% of our energy throughout the day This changes depending on your metabolic health, total size, and other stuff When you see people who just can’t sit still, they probably have a pretty high NEAT This also helps to explain how people can maintain the same amount of physical training (exercise performance) as well as health at tremendously different levels of calorie intakes because we can adjust NEAT very quickly There is a huge buffer where you can increase or decrease NEAT

• Andy adds, “ We can kind of change our metabolic set point if you will, to keep you at the same body size, irrelevant of going up and down in calories ”

• Otherwise it’s in rest mode

• NEAT accounts for about 10% of our energy throughout the day

• This changes depending on your metabolic health, total size, and other stuff
• When you see people who just can’t sit still, they probably have a pretty high NEAT

• This also helps to explain how people can maintain the same amount of physical training (exercise performance) as well as health at tremendously different levels of calorie intakes because we can adjust NEAT very quickly There is a huge buffer where you can increase or decrease NEAT

• There is a huge buffer where you can increase or decrease NEAT

How a muscle contraction works and why it requires ATP [48:00]

How does a contraction actually work and why does it require ATP?

• A signal from a nerve is needed to begin a contraction
• A nerve (or motor unit ) comes into a skeletal muscle In the eye, there is a single motor unit that comes in and activates each single muscle fiber; this gives an extraordinary control of dexterity In the glutes, in contrast, you need to contract with as much force as possible, but you don’t need a high fidelity or precision of movement Fingers are second to the eye in terms of fidelity of movement So if there is one to one (nerve to muscle fiber) in the eye, it could be one to thousands in the glutes Contracting the glutes on/off, at 50% of maximal force, at 20%
• The SAID principle is a specific adaptation for closed demand

• The Henneman’s size principle (named after the scientist Elwood Henneman ) says there are low threshold and high threshold motor units This means some motor units are very easy to turn on while others are more difficult

• In the eye, there is a single motor unit that comes in and activates each single muscle fiber; this gives an extraordinary control of dexterity

• In the glutes, in contrast, you need to contract with as much force as possible, but you don’t need a high fidelity or precision of movement
• Fingers are second to the eye in terms of fidelity of movement

• So if there is one to one (nerve to muscle fiber) in the eye, it could be one to thousands in the glutes Contracting the glutes on/off, at 50% of maximal force, at 20%

• Contracting the glutes on/off, at 50% of maximal force, at 20%

• This means some motor units are very easy to turn on while others are more difficult

How does a nerve deliver its signal?

• A contraction requires a fun interplay between chemistry, electricity, and chemistry
• You have to go from an electro signal to chemical signal back to electrical signal
• Sodium and potassium and chloride are your main players Chloride has a negative charge Potassium and sodium have a positive charge
• The fun way to look up this is to look at patient assisted suicide with Dr. Kevorkian You give a giant bolus of potassium to somebody and their heart is going to slowly stop contracting Why? Because the amount of intracellular potassium is going to become fairly equivalent to the amount of extracellular potassium And so the change in electrical gradient between the outside of the cell and the inside of the cell becomes neutral, and now no action potential occurs
• What you need to have happen is a change in electrical voltage from outside of the cell to inside the cell (typically we’re talking like negative 30 millivolts)

• Once enough of the sodium and potassium start moving in the correct directions (see the figure below), then the electricity changes because our positive is moved more negative, and boom, we hit this all or none switch

• Chloride has a negative charge

• Potassium and sodium have a positive charge

• You give a giant bolus of potassium to somebody and their heart is going to slowly stop contracting

• Why? Because the amount of intracellular potassium is going to become fairly equivalent to the amount of extracellular potassium And so the change in electrical gradient between the outside of the cell and the inside of the cell becomes neutral, and now no action potential occurs

• And so the change in electrical gradient between the outside of the cell and the inside of the cell becomes neutral, and now no action potential occurs

Figure 3. Movement of electrical charge and sodium during propagation of an action potential . Image credit: Medical gallery of Blausen Medical 2014

• And so skeletal muscle fibers can’t contract at different levels of force
• Once this action potential threshold occurs (you flick the switch), the muscle fully contracts The analogy Andy uses is a light switch Once you hit that certain threshold of millivolts, the muscle fiber contracts as hard as it possibly can There’s no dimmer switch here

• Once you get to that action potential, the millivolts just rocket back up and then there’s this whole cascade of recovery This is what your sodium, potassium pumps are doing to try to reset that gradient, put them back in the right direction so you can have another contraction This explains tetany ‒ if you can track that fiber multiple times in a row before it’s reset then it feels like it’s in an isometric contraction But what actually happens is you have so many muscle fibers contracting and relaxing at such a fast rate , it feels like the whole thing’s is locked up; but they’re actually flicking on flicking off

• The analogy Andy uses is a light switch

• Once you hit that certain threshold of millivolts, the muscle fiber contracts as hard as it possibly can

• There’s no dimmer switch here

• This is what your sodium, potassium pumps are doing to try to reset that gradient, put them back in the right direction so you can have another contraction

• This explains tetany ‒ if you can track that fiber multiple times in a row before it’s reset then it feels like it’s in an isometric contraction But what actually happens is you have so many muscle fibers contracting and relaxing at such a fast rate , it feels like the whole thing’s is locked up; but they’re actually flicking on flicking off

• But what actually happens is you have so many muscle fibers contracting and relaxing at such a fast rate , it feels like the whole thing’s is locked up; but they’re actually flicking on flicking off

Muscle fibers: modulation between fiber types with movement and changes in fibers with training and aging [53:15]

Explain how despite an all or none action potential and an all or none contraction of a single fiber, you can still get variable degrees of strength at the level of the muscle

• This is why Andy brought up Henneman’s size principle
• Within these motor units you have sizes
• Most of the time in normal situations, all the muscle fibers in that motor unit are of the same fiber type Let’s just say we had two motor units One of those motor units is slow-twitch and one of those motor units is fast-twitch fibers So if we had five fibers in that motor unit (or 500, it doesn’t really matter) we have a couple of factors coming on, but they’re generally going to be within that same motor unit

• Thinking about how we relegate force production is this‒ we know that once all five of those muscle fibers get turned on, they are going to contract at full speed

• Let’s just say we had two motor units

• One of those motor units is slow-twitch and one of those motor units is fast-twitch fibers
• So if we had five fibers in that motor unit (or 500, it doesn’t really matter) we have a couple of factors coming on, but they’re generally going to be within that same motor unit

The only way to change how much force is created in a whole muscle is by altering how many motor units get turned on

• So the size principle tells us we’re going to turn on the low-threshold units first

• And so if you go to do what you just did (reach over and grab a glass of water), it’s probably best we don’t turn on our high-threshold/ high force production units High-threshold/ high force production units are generally larger (not always) motor units that have faster fibers You don’t want to turn on your high-threshold units and produce unnecessary force Second, these high-threshold, fast-twitch muscle fibers burn more energy than slow-twitch muscle fibers (generally), and you don’t want to waste energy This is why your car starts off in first gear, then second, etc We lose efficiency as we go up but we gain performance

• High-threshold/ high force production units are generally larger (not always) motor units that have faster fibers

• You don’t want to turn on your high-threshold units and produce unnecessary force

• Second, these high-threshold, fast-twitch muscle fibers burn more energy than slow-twitch muscle fibers (generally), and you don’t want to waste energy This is why your car starts off in first gear, then second, etc We lose efficiency as we go up but we gain performance

• This is why your car starts off in first gear, then second, etc

• We lose efficiency as we go up but we gain performance

You always start with the smallest unit possible and turn on more motor units if more force production is required

(The mechanics/ molecular biology of a muscle contraction is revisited later, in the section‒ Differences between fast-twitch and slow-twitch muscle fibers [1:11:15])

Changes in muscle fiber types associated with aging and professional athletes [55:15]

How quickly is that response modulated in an athlete?

• Let’s say you want to deadlift something
• Initially, you’re going to activate the lower threshold motor units (these are almost exclusively slow-twitch fibers)
• The only way that we really know to increase that is through force production demands
• The challenge with fast-twitch muscle fibers is they’re only activated under high-threshold demands, which are high force demands
• Interestingly, with aging you see virtually no reduction in slow-twitch fibers (no reduction in size) More than a few papers show a hypertrophic effect of slow-twitch fibers with aging There is no loss in specific tension (which is like force per unit of size) There is no loss in power It appears to be very easy with any level of activity to maintain and preserve health of slow-twitch fibers
• But because fast-twitch fibers require force production and you generally don’t get high force production in activities of daily living, then those fibers go unutilized for long stretches of time Eventually they go away

• What we see happen is this really interesting thing called fiber type grouping , where the nerve will basically say, “ Okay, that fiber is being not used ,” and that whole motor unit will decay, and the fibers will be preserved The other neighboring motor units will actually grow new extensions, activate some of the previously gone motor units and then convert those fibers into whatever fiber type of that previous motor unit

• More than a few papers show a hypertrophic effect of slow-twitch fibers with aging

• There is no loss in specific tension (which is like force per unit of size)
• There is no loss in power

• It appears to be very easy with any level of activity to maintain and preserve health of slow-twitch fibers

• Eventually they go away

• The other neighboring motor units will actually grow new extensions, activate some of the previously gone motor units and then convert those fibers into whatever fiber type of that previous motor unit

In general, what we see happening is slow-twitch motor units start absorbing fast-twitch fibers and bringing them to their motor unit

• So we see these large patches of single fiber types throughout the muscle
• In a motor unit those fibers are connected by the same neuron and they’re the same fiber type, but they’re not laying next to each other You don’t want them in the same spot They’re sort of dispersed throughout the muscle And that gives you smoothness of contraction

• If you start punching, the entire right side of your bicep is one motor unit, the entire left side is another One of the things that happens when you contract that motor unit alone is you get super spastic, out of control, twitchy, unregulated movements

• You don’t want them in the same spot

• They’re sort of dispersed throughout the muscle

• And that gives you smoothness of contraction

• One of the things that happens when you contract that motor unit alone is you get super spastic, out of control, twitchy, unregulated movements

When we see this fiber type grouping thing occur with aging, it’s almost exclusively a problem of fast-twitch fibers, not loss of slow-twitch fibers. That also explains lack of fidelity as well as potentially some problems with fine unit movements.

What is the heterogeneity of fast and slow-twitch mixtures within different areas?

• Presumably the eye is all slow-twitch; it doesn’t require much force, but it does require a lot of speed
• Andy doesn’t know

• In big skeletal muscle like the lats or glutes , there is a huge amount of person-to-person variation

• There is also tremendous difference between muscle to muscle

• If you compared the soleus in two people, one person might be 90% slow-twitch and another 70% (the figure below shows the location of the soleus muscle in the lower leg) And there would be a large variation in that muscle
• If you look in animal models, you’re going to see 100% slow-twitch in the soleus
• The reasons is because we walk, the soleus has to be a majority slow-twitch muscle fiber We can’t risk any inefficiency in that system

• If you look at the shank in general, you’ve got two primary muscles of movement there (see the figure below) The soleus being the smaller one, it sits underneath the gastrocnemius at the bottom of the calf where it goes into that long piece They both attach at the bottom of your foot The gastrocnemius can be seen if you point your toe towards your face and flex your calf, it has a kind of U-shape that pops up in the middle The gastroc is almost exclusively fast-twitch but not nearly as exclusive as your soleus is The soleus is what we call postural or anti-gravity You can have a soleus contractor for hours and be totally fine, not even realize it If you had your gastroc contracted for more than a few seconds, you would feel a burn

• And there would be a large variation in that muscle

• We can’t risk any inefficiency in that system

• The soleus being the smaller one, it sits underneath the gastrocnemius at the bottom of the calf where it goes into that long piece

• They both attach at the bottom of your foot
• The gastrocnemius can be seen if you point your toe towards your face and flex your calf, it has a kind of U-shape that pops up in the middle
• The gastroc is almost exclusively fast-twitch but not nearly as exclusive as your soleus is
• The soleus is what we call postural or anti-gravity
• You can have a soleus contractor for hours and be totally fine, not even realize it
• If you had your gastroc contracted for more than a few seconds, you would feel a burn

Figure 4. Muscles of the leg. Image credit: NCI

Contrast the variation in the soleus with the VL (vastus lateralis) in the outside quad muscle

• The variation in the vastus lateralis gets extraordinarily large
• The VL is typically 50/50 fast-twitch/ slow-twitch and the record It gets far more complicated than a fast-twitch/ slow-twitch, but we’re keeping it at that level for now

• Andy’s lab biopsied a whole bunch of people who are Olympians, world caliber men and women, and the VL in some of those individuals are 80-85% fast-switch

• It gets far more complicated than a fast-twitch/ slow-twitch, but we’re keeping it at that level for now

Is this true across all sports? Would you expect a Tour de France champion to have that high fast-twitch muscle fibers in his VL?

• Some of the folks Andy biopsied involved in endurance exercise have as high as 90% slow-twitch in the VL So basically zero fast-twitch

• So basically zero fast-twitch

You can run the whole gamut of composition in the VL

• If you had a time machine and could go back and biopsy these same people as five-year-olds… we don’t know what they looked like then
• Andy got this kind of information with his twin study

Andy’s study of twins demonstrating the difference in muscle fibers between a trained and untrained individual [1:02:30]

• This was a study of monozygotic twins (identical) who had about 35 years of different training
• One of Andy’s graduate students who had been in the lab for three years was sitting next to Jimmy Bagley ; they were staring at a microscope, pulling out individual muscle fibers with tweezers for hours As they talked, this student commented on her Dad’s twin She mentioned that her Dad doesn’t exercise but her uncle has been competing in Iron Mans for 35 years Andy’s response was, “ Wait, wait, so let me get this straight. You have identical twin father, one of them has 30 plus years of documented endurance exercise. The other… has never exercised since high school… and you’ve been in my lab for three years .” It was a dream experiment
• They were able to bring them into the lab

• The uncle was a classic endurance nerd; he had documented every workout for 30 years (50 hand-written journals) They knew the caloric expenditure, the miles, half-marathons, marathons, everything

• As they talked, this student commented on her Dad’s twin

• She mentioned that her Dad doesn’t exercise but her uncle has been competing in Iron Mans for 35 years

• Andy’s response was, “ Wait, wait, so let me get this straight. You have identical twin father, one of them has 30 plus years of documented endurance exercise. The other… has never exercised since high school… and you’ve been in my lab for three years .” It was a dream experiment

• It was a dream experiment

• They knew the caloric expenditure, the miles, half-marathons, marathons, everything

Phenotypically, how different did they look?

• They looked almost identical
• The only difference was the non-exercising twin was a little bit less lean He had maybe 3-4 kg of body fat (6-9 lbs)

• Peter notes, “ It really speaks to the hereditary nature ” One is an exercise fanatic and the other is a couch potato but on the outside they look relatively equivalent Body habitus is remarkably hereditary; it’s on par with height and eye color

• He had maybe 3-4 kg of body fat (6-9 lbs)

• One is an exercise fanatic and the other is a couch potato but on the outside they look relatively equivalent

• Body habitus is remarkably hereditary; it’s on par with height and eye color

What did their muscles look like?

• Andy was super excited to study these twins
• He took every measure possible‒ DEXA scans, this is vertical jump, VO 2 max, blood chemistry, muscle biopsies, psychological evaluations with an IQ test
• Peter asked, “ How long did it take? Just so people understand the pace at which science moves from the microscope discussion until you’ve got these guys in your lab. ”

• Andy took the time to design the study, put in an IRB , etc…It took maybe 8 months

• Peter remarks on how fast this was, “ You already had the funding, I assume ”

• Andy didn’t wait for funding, he paid for their plane tickets out of his pocket

“ What’s interesting was that body composition lies ”‒ Andy Galpin

• The untrained person had 5-6 lbs more fat mass (maybe 3 kg was too high)

On DEXA, what was the difference in muscle mass?

• Around 100 g; Andy thinks the number was 71 (way beyond the detection limit of the machine)
• They were almost identical in muscle mass
• What’s interesting is that the endurance guy did not lift at all ( no strength training ) He did strictly running, cycling, swimming
• Peter asks, “ Can you imagine the experiment of triplets where you had a third guy here that only lifted weights? ”
• This question was an hour of Andy’s student’s thesis defense

• Andy did another study in Stockholm, Sweden with lifelong skiers People who were world champions in the 1940s-50s, and cross-country skiing Olympic gold medalists who didn’t stop competing Now they’re in the age of 85 plus up to 92 years old and they’re still competitive skiers Andy compared them to age-match healthy folks over here in America (we’ll come back to this)

• He did strictly running, cycling, swimming

• People who were world champions in the 1940s-50s, and cross-country skiing Olympic gold medalists who didn’t stop competing

• Now they’re in the age of 85 plus up to 92 years old and they’re still competitive skiers
• Andy compared them to age-match healthy folks over here in America (we’ll come back to this)

“ I’ve spent a little bit of time in this aging athlete thing ”‒ Andy Galpin

• Back to the muscle quality of the twins, one way leg extension strength is measured is by using echo intensity on an ultrasound while the subject perform a vertical jump These results were either identical or favored the non-exercising twin The same was true for total muscle mass
• Everything else that you would classically associate as an exercise adaptation favored the exerciser Blood lipid panel, blood pressure, body composition, VO 2 max, a higher resting heart rate, blood glucose
• Peter asks, “ Just to make sure I understand, the non-exerciser was stronger?”
• Yes, the non-exerciser was stronger, a better jumper, with higher quality muscle
• You can measure muscle quality with an ultrasound using echo intensity This is akin to measuring how much intramuscular fat is inside the actual tissue
• The exercising twin had more intramuscular lipid Peter asks, “ Isn’t that an adaptation to his endurance training where he wants to have more intramuscular lipid because he wants to have more logs near the fire, he’s burning those logs? ” Yes, Andy agrees This is different from the intramuscular lipid you see in a diabetic or someone with insulin resistance

• Peter finds it interesting that the strength metrics favored the non-exerciser Andy points out, “ It was all favored to neutral. Either some of the metrics were similar or not statistically different, but they hedged towards the non-exerciser… But there’s not a metric there that favored the exerciser on that side of the house. ”

• These results were either identical or favored the non-exercising twin

• The same was true for total muscle mass

• Blood lipid panel, blood pressure, body composition, VO 2 max, a higher resting heart rate, blood glucose

• This is akin to measuring how much intramuscular fat is inside the actual tissue

• Peter asks, “ Isn’t that an adaptation to his endurance training where he wants to have more intramuscular lipid because he wants to have more logs near the fire, he’s burning those logs? ”

• Yes, Andy agrees

• This is different from the intramuscular lipid you see in a diabetic or someone with insulin resistance

• Andy points out, “ It was all favored to neutral. Either some of the metrics were similar or not statistically different, but they hedged towards the non-exerciser… But there’s not a metric there that favored the exerciser on that side of the house. ”

Muscle biopsy results

• This is where there were big differences between the twins
• The quick version‒ the non-exerciser was almost identical to what you’d see in the literature, he had a mixed phenotype between fast-twitch and slow-twitch muscle fibers About 20% of his fibers were this hybrid format
• There are fast-twitch fibers and slow-twitch fibers , but the story goes much deeper

• These hybrids are a single individual cell One muscle fiber (aka muscle cell) co-expresses fast and slow twitch in different areas throughout the length of the fiber So the muscle fiber will be exclusively fast-twitch in one portion, fast- and slow-twitch in another portion, and exclusively slow-twitch in another portion

• About 20% of his fibers were this hybrid format

• One muscle fiber (aka muscle cell) co-expresses fast and slow twitch in different areas throughout the length of the fiber

• So the muscle fiber will be exclusively fast-twitch in one portion, fast- and slow-twitch in another portion, and exclusively slow-twitch in another portion

Microanatomy of fast-twitch and slow-twitch muscle fibers [1:11:15]

• Fast-twitch means the speed of muscle contraction is higher
• Fast-twitch fibers tend to be larger Though not always, not in endurance trained individuals and not with aging
• Fast-twitch fibers are more glycolytic driven They have more of the enzymes responsible for anaerobic glycolysis They have more glucose in the cell and less intramuscular triglycerides They generally have more phosphocreatine

• Slow-twitch fibers are fatigue resistant They can contract all day long They don’t use much glucose They are better at using fat as a fuel They tend to have more and larger mitochondria The downside is they don’t contract with as much velocity

• Though not always, not in endurance trained individuals and not with aging

• They have more of the enzymes responsible for anaerobic glycolysis

• They have more glucose in the cell and less intramuscular triglycerides

• They generally have more phosphocreatine

• They can contract all day long

• They don’t use much glucose
• They are better at using fat as a fuel
• They tend to have more and larger mitochondria
• The downside is they don’t contract with as much velocity

Figure 5. Slow-twitch and fast-twitch muscle fiber types in humans.

Is there a force difference between them or just velocity difference?

• In large part force production from muscle fibers is determined mostly by size‒ cross-sectional area
• So getting the fiber bigger is the play to get it faster
• Having said that, power is markedly different; power is force x velocity
• The metric Andy uses in single fiber experiments is specific tension , which is sort of like relative strength You take the size portion out of the equation

• What you’re going to see is a true slow-twitch; these are also called type I fibers

• You take the size portion out of the equation

Compared to a type I fiber (slow-twitch), a type IIa (fast-twitch muscle fiber) will have around 5-6X more power

• So it’s not a small difference when you normalize for size and cross-sectional diameter

• The IIx fibers is a special class of fast-twitch fiber, now you’re talking 20X that power Peter asks, “ Is that mostly explained by more metabolic apparatus? ” No

• Peter asks, “ Is that mostly explained by more metabolic apparatus? ” No

• No

Why does the IIx fiber go faster? Deep dive into what happens during a muscle contraction

• In the laboratory muscle fibers are differentiated by what’s called the myosin heavy chain
• Visualize how a muscle fiber works in 3D (see the figure below) Imagine a cylinder

• Andy explains it in 2D, but it actually occurs in 3D

• Imagine a cylinder

Figure 6. Structure of muscle. Image credit: Frontiers in Physiology 2019

• There are two microfilaments actin and myosin , and they overlap but they’re not touching each other Myosin is a big thick tube laying in the middle; it has these heads that flick off the top In the two figures below myosin is shown in purple and actin in green

• The myosin heads extend and reach up in 3D and grab onto actin Shown in the figure below; this refers to the sliding filament model of muscle contraction Myosin (making up the thick filament) is shown in purple in the figure below; actin (making up the thin filament) is shown in green

• Myosin is a big thick tube laying in the middle; it has these heads that flick off the top

• In the two figures below myosin is shown in purple and actin in green

• Shown in the figure below; this refers to the sliding filament model of muscle contraction

• Myosin (making up the thick filament) is shown in purple in the figure below; actin (making up the thin filament) is shown in green

Figure 7. Close-up view of myosin and actin in a muscle fiber. Image credit: OpenStax Anatomy and Physiology

• The idea is when you contract a muscle, myosin will reach outward and grab onto the actin, then pull the actin closer together The figure below shows a macro view of muscle contraction The green actin filaments on the left and right are brought closer together when the muscle contracts
• What actually happens in real life is those start stacking on top of each other

• And that’s why when you squeeze your bicep, it actually glows larger vertically because those muscle fibers are stacking on top of each other and actually elevating in size

• The figure below shows a macro view of muscle contraction

• The green actin filaments on the left and right are brought closer together when the muscle contracts

Figure 8. Macro view of a muscle contraction. Figure credit: OpenStax Anatomy and Physiology Figure 10.10

Force production is determined by cross-bridges

• What determines force production versus velocity is what we call cross-bridges
• Cross-bridges are the connection between myosin heads and actin The number of times these myosin heads grab onto actin, that little place of connection is called a crossbridge
• The more those cross bridges you have, the more effectively you can pull the actin closer to each other The faster the contraction The more force that contraction is going to be
• The thicker the myosin, the more likely it is to grab actin faster and stronger Compare it to grabbing something with your hands versus your fingertips and trying to pull it close to you

• There are six actin arranged in a circle surrounding each myosin in human skeletal muscle (depicted in the figure below)

• The number of times these myosin heads grab onto actin, that little place of connection is called a crossbridge

• The faster the contraction

• The more force that contraction is going to be

• Compare it to grabbing something with your hands versus your fingertips and trying to pull it close to you

Figure 9. Arrangement of actin filaments around a single myosin filament in human muscle.

How many heads does a myosin filament have?

• Bajillions
• Peter asks, “ Okay, so you have billions of heads to grab onto six potential targets. So you’re always going to grab a target. ”
• Yes, you’re going to grab one
• We can increase the amount of actin around each myosin fiber, but we see this in other animals Fruit flies and spiders can contract with much more force relative to humans because they have 8, or 10, or 12, or 20 actin per myosin (humans have 6)
• Andy summarizes, “ The more things I can give you to grab onto, the stronger you are ”

• Peter thinks there is somebody out there right now using CRISPR to figure out how to double the number of this arrangement in humans

• Fruit flies and spiders can contract with much more force relative to humans because they have 8, or 10, or 12, or 20 actin per myosin (humans have 6)

Andy has worked with some bear muscle tissue and it’s quite unique

• Humans have IIa and IIx (which was formerly and incorrectly identified as IIb)
• Most other animals do have IIb muscle fibers, and the IIb is even faster than the IIx
• Bears have extraordinarily high amounts of of IIb fibers, which allows them to go super fast

Do bears have more actin targets?

• Andy thinks this 6 to 1 ratio is pretty similar in mammals, but when you get to insects and things that number jumps off (but he would have to look this up to be sure)

Back to what determines the speed of contraction

• The myosin head is where the myosin connects to the actin, and part of it is called the heavy chain There is also a light chain portion
• The way we get a muscle to contract is ATP
• The myosin are loosely connected to the actin at all times, but in order for it to grab and pull, you need a strong connection For a strong connection to happen and for it to be able to pull it together, it requires energy
• A crude analogy is to imagine cocking a pistol Squeezing the trigger takes a lot less energy than cocking the pistol
• The energy we need from muscle contraction is not the pulling together; that’s almost passive It’s the cocking it back part that takes energy This energy comes from ATP
• On the tip of that myosin head is an enzyme called ATPase The – ase ending means it’s an enzyme ATPase hydrolyzes ATP, and that gives you energy to put that myosin back into place (at the starting point of the cycle, ready for another contraction) The figure below shows the movement of the myosin head throughout the contraction cycle
• Myosin cannot bind strongly until calcium comes into the picture

• Calcium is released from the sarcoplasmic reticulum and causes a conformational change in actin, thereby allowing myosin to connect to actin Part (a) of the figure below shows calcium binding to the thin filament (containing actin, shown in green) and this reveals the myosin binding site which allows myosin heads (shown in purple) to bind to actin Part (b) shows the cross-bridge formed when a myosin head binds actin Part (c) shows the power stroke where myosin uses the energy from ATP hydrolysis to move actin, this is the movement of a muscle contraction Now ADP is released and myosin can bind another ATP (for another contraction) Part (d) shows another ATP binding to the myosin head The ATPase on the myosin head hydrolyzes ATP→ ADP + Pi and the energy released is used to cock the myosin head back in the starting position shown in part (e) Part (e) the myosin head is now in a high-energy configuration and ready to form another cross-bridge to generate a muscle contraction

• There is also a light chain portion

• For a strong connection to happen and for it to be able to pull it together, it requires energy

• Squeezing the trigger takes a lot less energy than cocking the pistol

• It’s the cocking it back part that takes energy

• This energy comes from ATP

• The – ase ending means it’s an enzyme

• ATPase hydrolyzes ATP, and that gives you energy to put that myosin back into place (at the starting point of the cycle, ready for another contraction)

• The figure below shows the movement of the myosin head throughout the contraction cycle

• Part (a) of the figure below shows calcium binding to the thin filament (containing actin, shown in green) and this reveals the myosin binding site which allows myosin heads (shown in purple) to bind to actin

• Part (b) shows the cross-bridge formed when a myosin head binds actin
• Part (c) shows the power stroke where myosin uses the energy from ATP hydrolysis to move actin, this is the movement of a muscle contraction Now ADP is released and myosin can bind another ATP (for another contraction)
• Part (d) shows another ATP binding to the myosin head The ATPase on the myosin head hydrolyzes ATP→ ADP + Pi and the energy released is used to cock the myosin head back in the starting position shown in part (e)

• Part (e) the myosin head is now in a high-energy configuration and ready to form another cross-bridge to generate a muscle contraction

• Now ADP is released and myosin can bind another ATP (for another contraction)

• The ATPase on the myosin head hydrolyzes ATP→ ADP + Pi and the energy released is used to cock the myosin head back in the starting position shown in part (e)

Figure 10. Mechanism of a muscle contraction. Image credit: OpenStax Anatomy and Physiology

• Myosin connects and snaps as hard as it possibly can (part c in the figure above, the power stroke) This is why you can’t regulate force production It’s just going to catch and snap

• In order for Myosin to go back, you have to invest more ATP (part d and e in the figure above) As a side note, this explains rigor mortis ‒ a contraction happens but you don’t have the energy to then pull it back in; so you stay in a locked skeletal muscle contraction position

• This is why you can’t regulate force production

• It’s just going to catch and snap

• As a side note, this explains rigor mortis ‒ a contraction happens but you don’t have the energy to then pull it back in; so you stay in a locked skeletal muscle contraction position

The speed of ATPase determines single muscle fiber contractile speed

Myosin heavy chain is measured in the lab, and that’s how fast-twitch versus slow-twitch is determined

• You can use a technique called gel electrophoresis to compare different muscle fibers It uses a solid gel between two pieces of glass You put each individual muscle fiber in its own vertical lane You run an electrical charge through the gel (positive charge at the top and negative charge at the bottom), and the muscle fibers move through the gel You stop the electricity at some point, and the smaller fibers have moved further through the gel (because they are smaller, they move through the gel faster) You take a picture of the gel, and the muscle fibers that have gone down further are slow-twitch The muscle fibers that remain higher up in the gel are fast-twitch Molecular weight markers are used to confirm this

• It uses a solid gel between two pieces of glass

• You put each individual muscle fiber in its own vertical lane
• You run an electrical charge through the gel (positive charge at the top and negative charge at the bottom), and the muscle fibers move through the gel
• You stop the electricity at some point, and the smaller fibers have moved further through the gel (because they are smaller, they move through the gel faster)
• You take a picture of the gel, and the muscle fibers that have gone down further are slow-twitch
• The muscle fibers that remain higher up in the gel are fast-twitch
• Molecular weight markers are used to confirm this

This means the myosin heavy chain molecular weight determines the fiber type and that regulates its twitch ability

• The more heavy chains there are and the faster they work, the faster ATPase can operate, resulting in faster muscle fiber contraction

• That’s why muscle fiber type is not predicated on signs It’s specific to either metabolic abilities (in the old days) or twitch velocity (currently)

• It’s specific to either metabolic abilities (in the old days) or twitch velocity (currently)

Factors that determine one’s makeup of muscle fibers and how adaptable they are with training [1:22:15];

Understanding the biopsy studies in these identical twins

• The fiber profile of the untrained twin lines up very closely to what you will see in a textbook It’s around 50% slow-twitch and 30% fast-twitch IIa form About 20%+ is in this hybrid format

• It’s around 50% slow-twitch and 30% fast-twitch IIa form

• About 20%+ is in this hybrid format

What about IIx fast-twitch muscle fibers?

• When you get into the IIx conversation, the ability for humans to express IIx is extraordinarily rare
• What tends to happen is if you find somebody who has pure IIx fibers (IIx fibers that only express IIx), that muscle fiber has probably been deactivated for decades If you look at folks with a spinal cord injury and muscles that have been denervated for decades t hey as high as 50-60% of their total fiber being IIx The default strategy if the muscle is not activated or utilized, is for it to eventually become IIx We have no idea why
• IIx as a pure fiber type is the ultrafast one but it is extraordinarily rare Andy’s lab has gone through hundreds of thousands of individual fibers and have probably seen only 20-30 pure IIx fibers Maybe 0.1% of fibers are pure IIx
• There are hybrids‒ IIa/IIx (this hybrid is very common) , a triple hybrid (I/IIa/IIx this hybrid is uncommon),
• If you dive into the literature you’re going to get confused very quickly because a lot of people don’t use detailed enough methods to differentiate these fibers, and they’re going to say there are all kinds of IIx fibers This is not true There are IIa/IIx fibers If you don’t run high enough fidelity methods, you will pick up any fiber having some portion of IIx It’s a big deal to distinguish a fiber containing some IIx versus one that is purely IIx
• Andy points out, “ If you find somebody with a high percentage of 2X fibers, something odd is going on, the only exception here is there’s no data really on truly fast people .” We have a lot of data on powerful people‒ kayakers, bodybuilders, and weightlifters But we don’t have data on sprinters It’s hard to get these folks in the lab
• There is one case study , a guy who has the record for the 110-meter and 60-meter hurdles, and he had 24% pure IIx fibers Andy would like to see this replicated; he was a graduate student at the time of this study
• Peter asks, “ So the untrained guy was 50% slow (type I), 30% IIa, and 20% hybrid IIa/IIx… What about the cardio-only trained individual? ”

• The cardio-only trained individual was about 95% pure slow-twitch (type I muscle fibers)

• If you look at folks with a spinal cord injury and muscles that have been denervated for decades t hey as high as 50-60% of their total fiber being IIx

• The default strategy if the muscle is not activated or utilized, is for it to eventually become IIx We have no idea why

• We have no idea why

• Andy’s lab has gone through hundreds of thousands of individual fibers and have probably seen only 20-30 pure IIx fibers

• Maybe 0.1% of fibers are pure IIx

• This is not true

• There are IIa/IIx fibers
• If you don’t run high enough fidelity methods, you will pick up any fiber having some portion of IIx

• It’s a big deal to distinguish a fiber containing some IIx versus one that is purely IIx

• We have a lot of data on powerful people‒ kayakers, bodybuilders, and weightlifters

• But we don’t have data on sprinters It’s hard to get these folks in the lab

• It’s hard to get these folks in the lab

• Andy would like to see this replicated; he was a graduate student at the time of this study

Is this the explanation for why the trained twin was weaker, he just couldn’t generate force?

• It’s a couple things; #1 do they change?

We know muscle fiber types are highly malleable

• There is data on nutritional aspects that alter fiber type composition There are a whole host of nutritional interventions
• Anything that’s going to go activate PGC-1 alpha and that whole cascade
• There was a recent study on resveratrol , a reasonable 5 g dose in cattle (which is not much for a 2000-lb animal) caused significant changes in fiber type profile
• The question with these nutritional interventions is, does it change physical activity The answer is clear; this has been answered many times for so many decades
• But, we don’t know what these default for these people are One could argue the untrained guy was actually in an adaptation state, deviated away from his potential
• Andy notes, “ One thing that seems to be very clear is these IIa/IIx fibers are generally associated with poor health ”
• IIx by itself are irrelevant because they just don’t exist If you have them, it’s generally bad news You don’t want to train into them

• The ideal scenario here is IIa

• There are a whole host of nutritional interventions

• The answer is clear; this has been answered many times for so many decades

• One could argue the untrained guy was actually in an adaptation state, deviated away from his potential

• If you have them, it’s generally bad news

• You don’t want to train into them

If you do any sort of physical training, those hybrids tend to go down (IIa/IIx go away)

• Andy is not surprised that the trained twin had none of them (IIa/IIx hybrid type muscle fibers); it’s pretty textbook The figure below shows the distribution of muscle fiber type in the trained twin (TT) and untrained twin (UT)

• The figure below shows the distribution of muscle fiber type in the trained twin (TT) and untrained twin (UT)

Figure 11. Composition of muscle fiber type in the vastus lateralis . Image credit: European Journal of Applied Physiology 2018

• The magnitude of change between the twins is meaningful It’s only a case study, but it matters

• It’s only a case study, but it matters

What is your hypothesis, if there was a third brother (triplets) who was a weightlifter or powerlifter?

• Andy doesn’t think this would matter a ton, you would get the same answer
• He would not be surprised if the third brother was 70% fast-twitch (type IIa) and 30% type I

If they are trained, they will probably have very few hybrid type fibers

• The one distinction is the IIa/IIx fibers; they tend to be a little more responsive to workload (to get them to go away) So if you’re a laissez-faire lifter, you’ll still have these hybrids But if you’re training seriously, they are going to go away

• So if you’re a laissez-faire lifter, you’ll still have these hybrids

• But if you’re training seriously, they are going to go away

“ Given enough time and exposure, I don’t really think that there’s a limit to the plasticity among fiber types ”‒ Andy Galpin

• These twins had different exercise habits for 35 years

Do we have a sense about the window in which you have maximally plasticity in response to training?

• So if someone listening to this is 50-years-old and they have been sedentary a lot of their lives, but now they get the motivation to become big-time exercisers; Peter asks, “ How much can they bend the arc of their fiber curve? ”

• Andy points out, “ Fiber type is actually really quite cool because it doesn’t seem to matter what age you are ”

Training studies in 70-year-olds show dramatic changes in fiber type in six weeks, certainly eight weeks, and the magnitude of change doesn’t seem to differentiate

The way that you want to think about this is, it’s kind of like an asymptote

• The less trained you are, the faster the initial adaptation
• The closer you are to your edge, the slower the adaptation

• Andy compared world caliber weightlifters to national caliber lifters (summarized in the figure below) The world caliber lifters had been lifting at a very high level for 8 years The national caliber lifters had been lifting at this level for more like 4 years They saw the initial changes happened very quickly, but getting that last few percent changes in that second group took years

• The world caliber lifters had been lifting at a very high level for 8 years

• The national caliber lifters had been lifting at this level for more like 4 years
• They saw the initial changes happened very quickly, but getting that last few percent changes in that second group took years

Figure 12. Distribution of muscle fiber types in World-caliber females (WCF), National-caliber females (NCF), and National-caliber males (NCM). Image source: PLoS One 2019

In 4-6 weeks we can see a demonstrable change in fiber type composition, and it doesn’t seem to matter what age you are

Hypertrophy and what happens at the cellular level when a muscle grows [1:30:00]

When a person wants to have bigger muscles, what is happening at the cellular level with their muscle fibers?

• Hypertrophy generally refers to the diameter of the muscle fiber or cross-sectional area
• If you think about the muscle fiber as a cylinder, the width of the cylinder expands Think about that circle getting larger
• Peter compares this to a fat cell, “ A crude analogy is getting fatter means each adipocyte is getting bigger. It’s taking on and storing more triglyceride. ”
• For years “Bro science” has compared sarcoplasmic hypertrophy to contractile hypertrophy

• The question is‒ is the change coming from fluid retention or is it actually enhanced contractile tissue (which would be actin and myosin) It seems to be a little bit of both, and it happens in different phases of training

• Think about that circle getting larger

• It seems to be a little bit of both, and it happens in different phases of training

Do different types of training increase sarcoplasmic versus contractile hypertrophy?

• Peter asks, “ Is a bodybuilder a bodybuilder because their sarcoplasmic reticulum is huge, but their contractile units are not that much bigger than the average person? ”

• It’s what we call sarcoplasmic hypertrophy (not the sarcoplasmic reticulum), and this would be an increase in diameter In other words do all increases in muscle size through strength training happen because myosin actin are getting thicker? Remember you can’t add actin [filaments]

• In other words do all increases in muscle size through strength training happen because myosin actin are getting thicker? Remember you can’t add actin [filaments]

• Remember you can’t add actin [filaments]

We don’t know the answer to that question yet

• More data is coming out
• Even a few years ago, the idea that sarcoplasmic hypertrophy was a thing was thought of as garbage science The idea that anytime muscles got bigger, the contractile units were getting bigger

• Peter notes, “ I’m not shocked that that was the default hypothesis. I’m shocked that it wasn’t definitively known. ”

• The idea that anytime muscles got bigger, the contractile units were getting bigger

It’s a technology issue/ assay problem to figure out how to measure this

• The issue is the standardization of fluids
• When you sample the tissue, how do you lock the fluid into place
• How do you take this cell out of a living human and preserve its fluid architecture without contaminating it You can’t do this with liquid nitrogen, the flash freeze will create ice crystals
• Mike Roberts out of Auburn has produced a lot of interesting work in this area
• Preservation in liquid nitrogen is actually fine, but from there you have to thaw it correctly Mike Roberts spent a couple years trouble shooting this process
• Peter adds, “ I hope there’s some high school college kid listening to this who’s studying chemistry, who’s realizing just how cool and interconnected all of these worlds are. Chemistry, biology, physics, they’re just so linked. ”

• Andy always jokes that there’s only one science, it’s just math As much as he hates math, chemistry is math, energy is math, biomechanics is math Math and reductionism

• You can’t do this with liquid nitrogen, the flash freeze will create ice crystals

• Mike Roberts spent a couple years trouble shooting this process

• As much as he hates math, chemistry is math, energy is math, biomechanics is math

• Math and reductionism

Why is it that a bodybuilder can have more muscle, yet they’re not stronger than a strong man or a weightlifter?

• The easy sophomore answer is, “ Oh, neurological adaptations ”

• But there’s nothing happening intracellularly? Andy doesn’t think that’s correct, and it doesn’t look to be the case

• Andy doesn’t think that’s correct, and it doesn’t look to be the case

The juxtaposition

• There’s a thing called lattice spacing , which is there’s an optimal distance between that myosin and actin When trying to produce a powerful contraction, if myosin and actin are buttered up next to each other, they can’t actually squeeze that hard because there’s nowhere to go Likewise, if they’re too extended, then they can’t squeeze

• Peter adds, “ It’s the same idea as preload in a heart ” Preload is going to determine stroke volume, everything coming in Thinking about this spacing, if you start adding contractile units, then one way or another, you have to preserve the spacing somehow The idea is it will expand hyperotrophically only to the level…

• When trying to produce a powerful contraction, if myosin and actin are buttered up next to each other, they can’t actually squeeze that hard because there’s nowhere to go

• Likewise, if they’re too extended, then they can’t squeeze

• Preload is going to determine stroke volume, everything coming in

• Thinking about this spacing, if you start adding contractile units, then one way or another, you have to preserve the spacing somehow
• The idea is it will expand hyperotrophically only to the level…

There is a mathematical optimization for the exact strike distance between actin and myosin to not be overextended or under extended, a dn to have that perfect preload for maximum contraction

• Peter asks, “ If your hypertrophy training interfered with that and compromised it, you might gain size at the expense of potential strength ”

Fluids in muscle

• Andy adds another alternative, “ If that hypertrophy was coming simply from excessive fluid and not actually contractile fluids, then you would actually have a larger muscle ” These fluids are not acute fluid retention (not bloated water loading) Rather, there can be enhanced fluid in a homeostatic balance inside the tissue because the diameter has gotten larger, but it wasn’t met with an equal amount of increase in contract value
• People are familiar with the idea that about 70% of our weight is water Most of this water is in the cells of our body, and the muscle is no exception

• Going back to bodybuilding, Peter loves following Jay Cutler on Instagram He’s one of the guys who in retirement is still training hard and paying attention to his nutrition There was an interesting video where he went to In-N-Out Burger for his cheat meal He places this monster order, and what surprised Peter was how much he said, “ No salt, no salt ” He ordered two burgers and two fries, both with no salt Clearly this guy knows something about the effect of sodium on fluid retention This is a different fluid than what we are talking about now

• These fluids are not acute fluid retention (not bloated water loading)

• Rather, there can be enhanced fluid in a homeostatic balance inside the tissue because the diameter has gotten larger, but it wasn’t met with an equal amount of increase in contract value

• Most of this water is in the cells of our body, and the muscle is no exception

• He’s one of the guys who in retirement is still training hard and paying attention to his nutrition

• There was an interesting video where he went to In-N-Out Burger for his cheat meal He places this monster order, and what surprised Peter was how much he said, “ No salt, no salt ” He ordered two burgers and two fries, both with no salt

• Clearly this guy knows something about the effect of sodium on fluid retention This is a different fluid than what we are talking about now

• He places this monster order, and what surprised Peter was how much he said, “ No salt, no salt ”

• He ordered two burgers and two fries, both with no salt

• This is a different fluid than what we are talking about now

How athletes quickly cut water weight and the rehydration process [1:37:30]

• Andy works with a lot of athletes, and weight cut is a huge deal Managing 15+ lb reduction in water of the course of 48 hours and then putting that back in If you don’t understand being hyperosmotic or hyperosmotic or isosmotic, you’re going to cause a whole host of problems from kidney issues to diarrhea to bloating etc. You have to actually understand what you put back in them has to be the same thing as what’s intracellular or there’s a huge shift and you’re not going to drive fluid into tissues You get into situations where guys become severely dehydrated They’re peeing but very little fluid is getting into tissue because blood volume expanded so quickly without the electrolytes being balanced

• Managing 15+ lb reduction in water of the course of 48 hours and then putting that back in

• If you don’t understand being hyperosmotic or hyperosmotic or isosmotic, you’re going to cause a whole host of problems from kidney issues to diarrhea to bloating etc.

• You have to actually understand what you put back in them has to be the same thing as what’s intracellular or there’s a huge shift and you’re not going to drive fluid into tissues You get into situations where guys become severely dehydrated They’re peeing but very little fluid is getting into tissue because blood volume expanded so quickly without the electrolytes being balanced

• You get into situations where guys become severely dehydrated

• They’re peeing but very little fluid is getting into tissue because blood volume expanded so quickly without the electrolytes being balanced

What’s the rule of thumb on hydration?

• Before the podcast they were talking about how Peter had food poisoning, and in a span of two days he lost seven pounds Which is a lot for someone whose weight is very stable Let’s posit that 6.5 lbs of that weight loss was water

• Peter asks, “ What’s the ideal strategy to replenish that in terms of hyper-, hypo-, or iso- osmotic? ”

• Which is a lot for someone whose weight is very stable

• Let’s posit that 6.5 lbs of that weight loss was water

1 go slowly and make sure you don’t get too excessive

• Shoot for something in the neighborhood of 110-125% fluid weight because you’re going to lose some
• If you lost 7 lbs, go for 8-9 lbs or a gallon A gallon is 4 liters and a liter is a kilo, so your talking 4 kilos
• Drink that over the course of 3-4 hours

• Andy works with fighters who have to weigh-in for competition Last week a guy in Abu Dhabi weighed-in at 136 lbs and within five hours was back at 152 lbs With no urine, no diarrhea, no GI issues

• A gallon is 4 liters and a liter is a kilo, so your talking 4 kilos

• Last week a guy in Abu Dhabi weighed-in at 136 lbs and within five hours was back at 152 lbs With no urine, no diarrhea, no GI issues

• With no urine, no diarrhea, no GI issues

What’s the osmolarity of the fluid he took in?

• That can fluctuate depending on if the person is a high-salt or low-salt sweater
• It also depends on how much salt they pulled out of their diet that week Obviously you don’t pull out salt 5-6 days away from the weigh-in

• But if you have 7-8% of your weight in body fluid to lose, you’re going to take some salt out for a couple days to get there

• Obviously you don’t pull out salt 5-6 days away from the weigh-in

How many grams of sodium per day are they down to?

• You’re going down to zero on those last couple days
• A classic example is we might have them at 2.5 g
• On the day before, on water cut day, it’s zero So you’re boiling chicken to get as much possible stuff out and you’re eating as close to zero salt as possible for that 24 hour period

• Salt has a bigger impact than cutting calories at this point when you’re staring down the barrel of an 8-15 lb water cut in a day Peter finds this incredible that someone can go from 160 to 147 lbs in a day simply losing water

• So you’re boiling chicken to get as much possible stuff out and you’re eating as close to zero salt as possible for that 24 hour period

• Peter finds this incredible that someone can go from 160 to 147 lbs in a day simply losing water

What is an ideal time to lose 8-15 lbs of water weight?

• Ideally you come into a fight week hydrated on normal or even slightly higher salt, normal or higher carbohydrate
• You need to come in healthy, recovered, not over trained
• Monday through Thursday, you’re going to start getting off as much water passively as you can You will typically keep carbohydrates very low, 50 g or less depending on what you’re doing (this will help pull some water out)
• You can play games with fiber and have a low residue diet the last couple of days so you can make sure you’re not holding onto food in your gut That can buy you a couple of kilos, depending on the size of the person
• So Monday of fight week you might weigh 170 lbs and you can get down to 164-165 by Thursday with passive water loss
• Now 9 lbs need to be lost over 24 hours You’re going to float a couple throughout the day urinating (because you’re being very hydrated) You’re going to float one or so over night So this brings us to 3 lbs, and we have 6-7 lbs of active water dropping that needs to happen 15 lbs in a week is not that bad
• Peter asks about those 6 lbs, is this from complete sodium restriction?
• You’re going to have to add in some sort of sweat component, do sauna or something like that Ideally, you would do a little bit of physical activity to burn any last bit of glycogen without feeling too bad Then you do what’s called a mummy wrap‒ you lay down and put a bunch of blankets on yourself It’s very easy to regulate blood pressure and make sure you’re not at risk of passing out You’ll sweat a good amount
• Friday morning, 9:00 is weigh-in
• In the best case scenario, you don’t lose much the night before
• You wake up in the morning 4 lbs over and you can sweat out those 4 lbs pretty easily in a sauna (20 minutes)
• The fight is Saturday night; so, you’ve got 30-36 hours to put it back on
• You would ideally be back to your normal Monday weight within four to five hours after that weigh-in You’re only touching that final scale number for a very short amount of time
• So you’re back to that normal weight number by the next morning
• If you do it correctly you can have recovery of muscle glycogen in 36 hours

• The difficult part is getting brain fluid back Andy is not convinced that gets all the way back in 36 hours But there’s just no way around that

• You will typically keep carbohydrates very low, 50 g or less depending on what you’re doing (this will help pull some water out)

• That can buy you a couple of kilos, depending on the size of the person

• You’re going to float a couple throughout the day urinating (because you’re being very hydrated)

• You’re going to float one or so over night
• So this brings us to 3 lbs, and we have 6-7 lbs of active water dropping that needs to happen

• 15 lbs in a week is not that bad

• Ideally, you would do a little bit of physical activity to burn any last bit of glycogen without feeling too bad

• Then you do what’s called a mummy wrap‒ you lay down and put a bunch of blankets on yourself It’s very easy to regulate blood pressure and make sure you’re not at risk of passing out You’ll sweat a good amount

• It’s very easy to regulate blood pressure and make sure you’re not at risk of passing out

• You’ll sweat a good amount

• You’re only touching that final scale number for a very short amount of time

• Andy is not convinced that gets all the way back in 36 hours

• But there’s just no way around that

The advantage of a fighter who weighs-in at 147 lbs and lives/ trains at 150 instead of 160

• Peter thinks this person has the physiological advantage of going through less metabolic shift in the two days prior to the fight
• The drawback is they are going to weigh less in the ring
• There is a good amount of research looking at performance testing pre and post this weight loss
• Actually, it’s not that bad from a performance perspective as long as you stay within certain reigns
• Look at the UFC fighter Frankie Edgar , he’s won multiple world championships and is significantly undersized; so that works
• In general, it starts to become challenging in MMA because the weight classes are so large
• In boxing you’ve got a weight class every 4-7 lbs So if a guy is really 6 lbs heavier than you, it’s not a big deal
• It’s different if a guy is 15 lbs heavier than you in a grappling sport
• In an idea situation, nobody cuts weight; but how do you ever do that?

• If you come into fight week 6% over fight weight, it should be no problem performance wise to get to that weight When you come in at 10% over your fight weight, it’s going to be really, really challenging

• So if a guy is really 6 lbs heavier than you, it’s not a big deal

• When you come in at 10% over your fight weight, it’s going to be really, really challenging

Different types of athletes [1:47:30]

Comparing athletes

• Think about different types of athletes that are a beacon of excellence in anything that has to do with muscle
• A powerlifter is the strongest athlete at the all out one-rep max
• The Olympic weightlifter who is also doing a one-rep max had to be incredibly coordinated because of the nature of the movement, they are incredibly explosive (but it’s just one rep)
• The strongman is throwing boulders and having to pick them up and throw them again and again This is an insane amount of strength You’re not relying on just one energy system You’ve got to have a little bit of endurance, both muscularly and cardiovascularly
• The CrossFit athlete , is also very strong and is agile, mobile He isn’t as good as any of the first three, but has something none of them have, which is a greater degree of endurance
• The bodybuilder aesthetically looks better than all of them, has bigger muscles, but meets no other requirement
• You could argue that the sprinter has the highest ratio of power to weight and has optimized locomotion

• Peter remarks, “ I will never be half as good as any of those six. And most people listening to this don’t need to be, but we probably want bits of each of them in us. ”

• This is an insane amount of strength

• You’re not relying on just one energy system

• You’ve got to have a little bit of endurance, both muscularly and cardiovascularly

• He isn’t as good as any of the first three, but has something none of them have, which is a greater degree of endurance

Training advice for a hypothetical client who’s untrained and wants to add muscle and functional strength for longevity [1:49:45]

Hypothetical patient:

• They were active in highschool and college, but over the last 10 years, their only exercise has been activities of daily living (hiking with the kids, etc.)
• They have started doing a couple of hours of week of zone II on the bike, but they don’t know how to approach strength training
• They are willing to put three hours a week in the gym, 1 hour at a time
• Their DEXA scan shows that their ALMI is about 40th%
• They want to aim for the 75% for lean mass (or above) in 2-3 years
• They also want to be stronger; they want to be able to do stuff when they get older

• Peter asks “ What other questions do you have for them before you design their program? ”

• Andy remarks, “ You’ve basically described every one of our executive clients in our Rapid Health Optimization program ” They have zone II knocked out (at a couple hours per week); that’s steady state

• They have zone II knocked out (at a couple hours per week); that’s steady state

“ We need hypertrophy. This is a basic foundation of everything .”‒ Andy Galpin

• You’re going to get stronger by doing hypertrophy, at this stage of your training
• This is not always coupled; you can get stronger without getting more muscle mass, and you can get a lot of muscle without optimizing strength

Spending time initially getting physically fit before trying to add muscle mass for someone like this is a very fruitful investment

• A study came out more recently showing six weeks of endurance exercise (steady state cycling) prior to hypertrophy, actually enhanced muscle growth
• At this stage there is not an interference effect, but zone II exercise is complimentary

*(This discussion is continued at time stamp [1:59:30] AND is fully summarized at the end of the show notes)

Changes in muscle and muscular function that occur with aging [1:53:45]

• Andy notes, “Y ou also mentioned, you said three years from now or something, which tells me your mind is really thinking about long term investment here… One of the things that you’ll see very specifically with aging is a loss of physical function, and that’s more geared for power .”
• As you age, the rate of loss of muscle mass is something like 0.5-1% per year
• Loss of muscle strength is double or triple that

• Loss of muscle power is triple that; you see a very precipitous drop in muscle power Why is that happening? The loss of speed explains a little bit; look at the world record in the 100-meter dash for different age groups (see the table below)

• Why is that happening?

• The loss of speed explains a little bit; look at the world record in the 100-meter dash for different age groups (see the table below)

Figure 13. Work record in 100-meter dash by age . Image credit: Wikipedia

• Andy notes that in strength sports (like powerlifting), the world record doesn’t go down that much with age

• Andy’s friend Greg Grosicki just published a paper in the Journal of Physiology looking at how at single fiber contractile function changes with aging The data here are extraordinarily clear You see very little loss of function in the slow-twitch fibers with aging (regardless of exercising or not) But you see a dramatic reduction in the fast-twitch fibers But you don’t see a drop of power

• The data here are extraordinarily clear

• You see very little loss of function in the slow-twitch fibers with aging (regardless of exercising or not)
• But you see a dramatic reduction in the fast-twitch fibers
• But you don’t see a drop of power

So there’s nothing internal to the muscle fiber that’s going down with aging; it’s atrophy of fast-twitch muscle fibers

“ The atrophy of fast-twitch fibers is the almost exclusively the problem with aging muscle ”‒ Andy Galpin

• There is some loss of total muscle fiber, but that is actually very difficult to find scientifically Counting the total amount of fibers in a live human muscle is extraordinarily difficult

• Thinking about longevity, absolute force and power has to be preserved, and the issue here is fiber atrophy

• Counting the total amount of fibers in a live human muscle is extraordinarily difficult

Peter’s takeaway :

• At age 50, you want to live for another 40 years and be functioning
• The most important thing to do in the gym is focus on what is declining rapidly ( fast-twitch muscle fibers )
• If you focus on what’s declining then as a corollary, you’re going to get a bunch of other stuff for free

• If you ignore the decline of fast-twitch muscle fibers, you might as well be the high exercise twin who only does cardio “ He’s going to be this hyper-cardio athlete who’s still a decrepit person in the last decade of their life ”

• “ He’s going to be this hyper-cardio athlete who’s still a decrepit person in the last decade of their life ”

Fast-twitch fibers require specific types of training

• Slow-twitch fibers are going to get activated with any activity of daily living Whether you’re doing zone 2, zone 6, whatever you want
• Slow-twitch fibers are good but fast-twitch fibers require attention;
• You can’t accidentally get fast-twitch fibers Just like you can’t accidentally get too muscular

• We also know you have to take care of VO 2 max (covered in a previous podcast )

• Whether you’re doing zone 2, zone 6, whatever you want

• Just like you can’t accidentally get too muscular

Training plan for the hypothetical client [1:59:30]

Basic info

• For the person starting out, you also have to be considerate of their lack of training in the previous 10 years In the previous episode with Holly , she talked about starting out with a very low volume (way lower than you would think)
• Andy is going to be very cautious of eccentric movements as they will generate more soreness You want to build some muscle mass without getting excessively sore

• You also want to start building movement patterns that you will need over time Think of this as an investment We want to get good at these movements so we don’t pick up injuries later

• In the previous episode with Holly , she talked about starting out with a very low volume (way lower than you would think)

• You want to build some muscle mass without getting excessively sore

• Think of this as an investment

• We want to get good at these movements so we don’t pick up injuries later

Andy’s advice for the first six months

• Zone 2 training is covered with two hours a week
• Start with 1-3 working sets of 4 exercises a day
• You want to spread those across the upper and lower body, and use different movement patterns
• You want to practice compound movements (not isolated/single joint movements, yet)

Spend 30 minutes on these exercises

• Learn how to do a goblet squat You’re going to hold the dumbbell in front of your chest
• Learn to do a hip extension

• Learn to do a basic overhead press or some bent rows

• You’re going to hold the dumbbell in front of your chest

The goal is to get the movement pattern down and master the foundational stuff before you start progressing the load

• Brace your spine in the proper position
• Breathe through your nose and through the proper position
• Is your neck in the right spot?

Advice for the second six months

• The hypothetical person enjoys going to the gym but can’t commit any more than three, 60-minute sessions a week This is in addition to two hours a week of zone 2 training

• Their goal is to get bigger, stronger, and more functional

• This is in addition to two hours a week of zone 2 training

Address power and speed in the first 10-15 minutes

• First, we need to we need to introduce those movement patterns and those velocities and those tissue tolerance (not focus on the creation of power) Your ability to land and absorb should focus on‒ How did I stop that movement? How do I land from it?

• Do a box jump ‒ jump from the ground and land on a box that is 18-inches in the air Practice that movement pattern Land on the box (not on the ground), because that reduces the eccentric landing There should be no fatigue This is simply about load tolerance and introducing power You’re going to start learning how to move fast, but you’re going to do it in a safe way where you’re not going to pull a hamstring

• Your ability to land and absorb should focus on‒ How did I stop that movement? How do I land from it?

• Practice that movement pattern

• Land on the box (not on the ground), because that reduces the eccentric landing
• There should be no fatigue
• This is simply about load tolerance and introducing power
• You’re going to start learning how to move fast, but you’re going to do it in a safe way where you’re not going to pull a hamstring

Benefits of power and speed work for preventing injury

• Just to be clear, this person is not competing in sports; all they want to do is be able to pick up their grandkids in 20-30 years The box jump is needed to prevent injury
• Andy adds, “ Do you know what puts people in an assisted living home? Falling and breaking a hip. ”
• The connection between morbidity and mortality with a hip break is extraordinary after the age of 60 (it’s not even 90)
• A large reason why people fall is they don’t have foot speed If you catch your toe on the corner or you slip You need the foot speed to be able to put your other foot (or that foot back out in front of you) in the proper position Then you have to have the eccentric strength to stop that fall Andy summarizes, “ You need foot speed to get there and then eccentric strength to brace the fall so you don’t land and break your hip. That’s what’s going to keep you playing with your kids when you’re 60. ”
• This is just 10 minutes of your workout

• Peter had a patient explain his goals for aging‒ he wanted to always be able to go see his grandkids He meant this both micro and macro He never wanted to be in the position where he was not physically able to get on an airplane and travel If he goes on a hike with his grandkids, he’ll need to be able to get up and do a little scramble (and then help his grandkid get up on that rock) You’ve got to have a little pot to get up there

• The box jump is needed to prevent injury

• If you catch your toe on the corner or you slip

• You need the foot speed to be able to put your other foot (or that foot back out in front of you) in the proper position
• Then you have to have the eccentric strength to stop that fall

• Andy summarizes, “ You need foot speed to get there and then eccentric strength to brace the fall so you don’t land and break your hip. That’s what’s going to keep you playing with your kids when you’re 60. ”

• He meant this both micro and macro

• He never wanted to be in the position where he was not physically able to get on an airplane and travel

• If he goes on a hike with his grandkids, he’ll need to be able to get up and do a little scramble (and then help his grandkid get up on that rock) You’ve got to have a little pot to get up there

• You’ve got to have a little pot to get up there

Back to the first 10 minutes‒ work on power, speed, and agility

• In that first 10 minutes, you have box jumps with landing on top, bounds , skips , medicine ball throws are great (medicine ball tosses up in the air as high as you can go as far as you can go behind you), medicine ball slams

• These are reinforcing movement patterns you’ve built the previous six months‒ proper hip extension versus low back extension It’s also what we call triple extension ‒ extending the hip, knee, and ankle

• It’s also what we call triple extension ‒ extending the hip, knee, and ankle

This is a very important human movement pattern. You can do that without jumping and landing by throwing a medicine ball, tossing it.

• If you go to plyometrics , you have to be a little bit careful here Plyometrics are totally safe for all ages; as long as you count for volume You just can’t do too many of them at too high of an intensity, in this case the eccentric load A five-minute jump rope is just plyometrics When you go single leg to single leg, you start increasing risk The hopscotch is just two-legged plyometrics to single leg to back forward progression lateral (a wonderful little exercise)
• Andy loves sprinting‒ it feels great/ terrible
• Do a 15-second, 70% sprint; then slowly come back down; wait a minute or two to fully recover Then roll back into it 2, 3, 4 seconds, and then pick it up for five seconds, six seconds; then, slowly back down

• One last example, from middle school and high school sports is playing racquetball or two on two badminton for a warmup You can do a lot of little different things that are going to be multi-point targeting going to be speed, agility, change of direction, quickness at this point

• Plyometrics are totally safe for all ages; as long as you count for volume

• You just can’t do too many of them at too high of an intensity, in this case the eccentric load
• A five-minute jump rope is just plyometrics When you go single leg to single leg, you start increasing risk

• The hopscotch is just two-legged plyometrics to single leg to back forward progression lateral (a wonderful little exercise)

• When you go single leg to single leg, you start increasing risk

• Then roll back into it 2, 3, 4 seconds, and then pick it up for five seconds, six seconds; then, slowly back down

• You can do a lot of little different things that are going to be multi-point targeting going to be speed, agility, change of direction, quickness at this point

Suggestions for planning the warm-up for three gym workouts each week

• Monday‒ do stuff with the medicine ball
• Wednesday‒ play pickleball
• Friday‒ do some jump stuff and medicine ball horizontal throws
• Other options‒ jump rope, hopscotch, bounding broad jumps

“ Honesty, you’ll be surprised… but that stuff’s actually kind of fun ”‒ Andy Galpin

• After 10-15 minutes of this, you’re hot and ready to move into strength training
• Keep the same structure of a total body workout on all three days Why? Because once a month, you’re going to miss one of those days (or more), and if you do body part splits you’ll start missing big things
• You can do a different rep range on each day
• Monday: 3-4 sets of 5-7 reps You’ll be able to use heavier weights You’ll have a 1.5 minute rest in between each one Aim for a RPE of 7-8 so you’re ending up with maybe two reps left in the tank
• Wednesday: go 15-20 reps per set You’re probably going to drive less soreness, because you’re activating less fast-twitch fibers You’re going to get more of a pump As you push the repetitions, you can work harder and feel a little less sore and more acute satisfaction

• Friday: you could do something like isometrics , where you’re just holding positions This is very good for joints and connective tissue It’s good to do something different

• Why?

• Because once a month, you’re going to miss one of those days (or more), and if you do body part splits you’ll start missing big things

• You’ll be able to use heavier weights

• You’ll have a 1.5 minute rest in between each one

• Aim for a RPE of 7-8 so you’re ending up with maybe two reps left in the tank

• You’re probably going to drive less soreness, because you’re activating less fast-twitch fibers

• You’re going to get more of a pump

• As you push the repetitions, you can work harder and feel a little less sore and more acute satisfaction

• This is very good for joints and connective tissue

• It’s good to do something different

All three of these are equally effective for hypertrophy

• Now that you’ve introduced three different elements, your gains in muscle size are going to be identical across the board

What drives muscle hypertrophy? [2:12:15]

Why is it that isometric training can elicit the same hypertrophy response as isotonic or movement-based contraction?

• Isometric is a forced muscle contraction without movement
• A big part of Peter’s recovery from shoulder surgery began with humeral extension (inflection without movement) Peter had a labral repair, see the podcast with Alton Barron
• He had not spent much time doing isometrics outside of that The exception was isometric deadlifts; he used isometric training to warm up as a precursor to deadlift
• For example, if you do a biceps curl, you can get every range of the bicep, but is there an isometric benefit to begin in one position versus another?

• Andy asks, “ Are you 10% flexion, 30% flexion, 110% flexion? ” He could go on about this topic for three hours Clearly we are going to do a part-two of this podcast

• Peter had a labral repair, see the podcast with Alton Barron

• The exception was isometric deadlifts; he used isometric training to warm up as a precursor to deadlift

• He could go on about this topic for three hours

• Clearly we are going to do a part-two of this podcast

The question is‒ what is actually driving muscle hypertrophy?

• It’s not the workout per se, it’s the stimuli
• What are those stimuli? That’s a whole conversation

• The reason hypertrophy is training wise (in terms of what reps to do, what type of exercise) is because the mechanisms are spread across different areas You can go from A, B, or C You don’t have to have all three You can get there using A and B or A and C, and so it’s very easy to land accidentally in the hypertrophy range as long as a couple of things happen

• You can go from A, B, or C

• You don’t have to have all three
• You can get there using A and B or A and C, and so it’s very easy to land accidentally in the hypertrophy range as long as a couple of things happen

As long as sufficient overload occurs, you’re going to get there

• Overload can happen over time with different strategies for progression Move volume More reps per set More weight Extra range of motion
• Isometrics is going to activate a number of those same mechanisms and cause the same amount of hypertrophy

• The primary downside of isometric is range of motion, and this is where you can mix it up

• Move volume

• More reps per set
• More weight
• Extra range of motion

Consider the position and muscle stretch

• In general, muscles respond best to being at the higher stretch So if you can have that thing at the highest level of extension But it depends on the muscle
• You can actually take a muscle fiber and hang it vertically with a weight at the end of it and it will grow
• Being stretched that long is a very strong signal to grow

• When you generally train a muscle over a large range of motion, you’re putting the muscle on a larger stretch, and that signal alone activates a whole anabolic cascade for hypertrophy

• So if you can have that thing at the highest level of extension

• But it depends on the muscle

If you’re going to do an isometric, Andy recommends you do it closer to the end range of motion where it feels the most tight, not the finish position

• But it very much depends on what you’re after
• The tricky thing is that many muscles are single joint
• Take the the soleus for example We talked about it earlier; it’s the muscle that crosses the ankle joint only
• In contrast, the gastroc crosses the knee and ankle joint
• So putting the soleus in the right position is only dependent upon the ankle, but putting the gastroc in the right position is dependent upon the ankle and knee If the knee is flexed, you’re never going to get the gastroc to contract properly You have to have an extended knee and extended ankle, because it’s going to get short on one end of that spectrum The same thing happens with the biceps muscle
• Peter asks, “ So a seated calf raise only works the soleus. A standing calf raise works both the gastroc and soleus? ”
• Correct
• The same it true with a triceps push down versus an overhead triceps extension behind the neck The triceps muscles across the shoulder joint are now going to be put on stretch when you go behind the neck
• Peter recently saw a study looking at triceps extension in the flexed versus extended humeral position The difference in muscle mass as significant when the arm was up (when the humerus was flexed)

• Andy agrees, muscles respond to being stretched He sees this with the hamstrings and with the glutes

• We talked about it earlier; it’s the muscle that crosses the ankle joint only

• If the knee is flexed, you’re never going to get the gastroc to contract properly

• You have to have an extended knee and extended ankle, because it’s going to get short on one end of that spectrum

• The same thing happens with the biceps muscle

• The triceps muscles across the shoulder joint are now going to be put on stretch when you go behind the neck

• The difference in muscle mass as significant when the arm was up (when the humerus was flexed)

• He sees this with the hamstrings and with the glutes

This changes in a situation where there is pain

• Some people have nagging elbow pain when they do a lot of bicep curls, etc. Can you train the biceps without aggravating the elbow? This is hard because all brachialis are going to cross the elbow joint

• What about a nagging shoulder problem ? If you do a preacher curl (where you arm is out in front of you), you’re shortening the biceps part that crossed the shoulder joint, but you can still work across the elbow joint and not aggravate your shoulder If you were to do an incline curl (where your shoulder and arm was behind you), you’re putting it on stretch across your shoulder joint and now those bicep curls could theoretically aggravate your shoulder

• Can you train the biceps without aggravating the elbow?

• This is hard because all brachialis are going to cross the elbow joint

• If you do a preacher curl (where you arm is out in front of you), you’re shortening the biceps part that crossed the shoulder joint, but you can still work across the elbow joint and not aggravate your shoulder

• If you were to do an incline curl (where your shoulder and arm was behind you), you’re putting it on stretch across your shoulder joint and now those bicep curls could theoretically aggravate your shoulder

More about isometric exercise [2:18:00]

• The benefits of isometric exercise depend on your specific surgery and what your therapist had you doing
• You want to activate the joint a little but not aggravate it You want to let things recover

• A powerlifter may want to train in the final position of their squat, and get very used to being strong there Going extra depth will make you worse as a lifter, because you’re not traveling a further distance and have to do more work

• You want to let things recover

• Going extra depth will make you worse as a lifter, because you’re not traveling a further distance and have to do more work

There’s no easy answer, and one of the reasons why we generally frown on isometrics is they take a lot of intention

• It’s easier to do a normal, full-range squat; then you don’t have to guess

How to properly incorporate isometric exercises into a workout [2:19:00]

If you had an athlete who was willing to do a little bit of isometric exercise

• Take the squat, for example Peter asks if you would load the bar in a low position, and stand under a weight that is much heavier than you could ever lift, and basically push up against the bar
• You can do an isometric squat in a number of ways, a bench or a squat Typically Andy would put the bar belt in the rack like a squat rack You have safety pins that run horizontal (perpendicular to the ground) Instead of putting the bar on top of those, you put the bar below them so you lift up against the rack and nothing moves You can set your position to push up on those Whether you’re putting it behind your neck for a squat Or putting a bench below it

• In the lab, Andy had built on the bottom of this a force plate that allows them to measure force produced in the ground at various positions

• Peter asks if you would load the bar in a low position, and stand under a weight that is much heavier than you could ever lift, and basically push up against the bar

• Typically Andy would put the bar belt in the rack like a squat rack

• You have safety pins that run horizontal (perpendicular to the ground)
• Instead of putting the bar on top of those, you put the bar below them so you lift up against the rack and nothing moves

• You can set your position to push up on those Whether you’re putting it behind your neck for a squat Or putting a bench below it

• Whether you’re putting it behind your neck for a squat

• Or putting a bench below it

Does isometric offer any other advantage over safety?

• There are a ton of advantages

• You have less degrees of freedom, less moving parts For example, if you get in a squat and your spine looks good and everything looks good, there’s a very low likelihood you’re going to get out of position The back squat is extraordinarily complicated; there’s a lot of moving parts There are degrees of freedom at the ankle, knee, hip, low back, ribs, shoulder, neck

• For example, if you get in a squat and your spine looks good and everything looks good, there’s a very low likelihood you’re going to get out of position The back squat is extraordinarily complicated; there’s a lot of moving parts There are degrees of freedom at the ankle, knee, hip, low back, ribs, shoulder, neck

• The back squat is extraordinarily complicated; there’s a lot of moving parts

• There are degrees of freedom at the ankle, knee, hip, low back, ribs, shoulder, neck

“ In an isometric, nothing moves. All we have to deal with is compression. ”‒ Andy Galpin

• Sometimes compression (specifically axial loading) is aggravating, but axial loading is also fantastic for long movements
• Andy added isometrics in for a client for the purpose of low risk and getting a lot of stimuli without having to worry about getting in position at different parts

Benefits of lifting with bands

• There is a thing called a strength curve , and when you do a typical isotonic movement (a normal lift), you’re only challenged in the areas in the range of motion where you’re the weakest

• Andy did a study on lifting with bands, using heavy bands for a deadlift He found there was a very low load at the bottom; as much as a 40% reduction in load at the bottom But when you come up and start crossing the knee joint and start gaining mechanical advantage, it becomes extraordinarily easy, but the bands start getting heavier So the actual tenacity that happens throughout the entire thing is greater at the top This is why people use bands (and chains and things) to train the whole area of the strength curve

• He found there was a very low load at the bottom; as much as a 40% reduction in load at the bottom

• But when you come up and start crossing the knee joint and start gaining mechanical advantage, it becomes extraordinarily easy, but the bands start getting heavier
• So the actual tenacity that happens throughout the entire thing is greater at the top
• This is why people use bands (and chains and things) to train the whole area of the strength curve

Bands allow you to be able to produce more resistance in areas where you’re stronger while not being held back by the weakest position

• You can the use isometric to go into that weakest position without having to put a whole bunch of load on your body
• You can get into an RDL position (Romanian deadlift, like a hinge), which is a complicated movement, and you can grab and pull as hard as you want and nothing moves
• It’s very difficult for people with a low training age to truly express maximum force output on a free range motion, because there are too many variables Am I in the right position? Is my back safe? Am I losing my balance?

• It’s easier to just say, “ Grab this bar and pull on it as hard as you possibly can ”

• Am I in the right position?

• Is my back safe?
• Am I losing my balance?

Walk me through how you do that for an RDL-Romanian deadlift-(a kettlebell, dumbbell, and barbell RDL)

• Set the barbell in the squat rack, and set the height of the safety pins to w whatever height feels comfortable for you You will pull up against that bar and nothing will move Your back will feel comfortable wherever that range of motion is for you Your glutes can be there; your feet can be in the right position You’ll get total foot, big toe activation

• You would start this things two-footed, but could do it one-legged

• You will pull up against that bar and nothing will move

• Your back will feel comfortable wherever that range of motion is for you Your glutes can be there; your feet can be in the right position You’ll get total foot, big toe activation

• Your glutes can be there; your feet can be in the right position

• You’ll get total foot, big toe activation

The goal is to express peak force output while feeling comfortable

• Stay in this isometric position for three seconds
• Some of Andy’s athlete’s will go up to five minutes on isometric holds They’ll do a rear foot elevated split squat, isometric hold for up to five minutes, which presents a tremendous neurological challenge
• Peter reacts, “ I’m generally up for things that are ridiculous. I don’t know if I could do it .”

• Andy asks, “ Have you ever done super high volume lunges or split squats like hundreds, things like that? ” The other day, Peter did a four-minute set of split squats Andy suggests getting into that position (or have your foot elevated just a little bit), and hold it for two minutes In this particular scenario you don’t need to create any resistance; time will be your resistance It’s isometric only in that you are just holding a position It’s like a better version of a wall squat; you can go for a long time

• They’ll do a rear foot elevated split squat, isometric hold for up to five minutes, which presents a tremendous neurological challenge

• The other day, Peter did a four-minute set of split squats

• Andy suggests getting into that position (or have your foot elevated just a little bit), and hold it for two minutes

• In this particular scenario you don’t need to create any resistance; time will be your resistance It’s isometric only in that you are just holding a position It’s like a better version of a wall squat; you can go for a long time

• It’s isometric only in that you are just holding a position

• It’s like a better version of a wall squat; you can go for a long time

Back to the hypothetical patient

• The third day could be a whole day of isometrics
• You could hold plank as an isometric exercise
• Hold a hip extension position and make sure your glutes are on and utilized
• You can do a squat in a couple of ways You can go all the way down and hold that bottom position for 30 seconds (this is challenging if you don’t have the right positioning) Andy would cap this when you break position (not when you get fatigued)

• One of the tests Peter does with patients is to see how long they can hold a full 90-degree squat (with the thigh parallel to the ground) 2 minutes is excellent You don’t fail when you give up, but when you make a compensatory movement (shoot your butt out or lunge forward) This is a great test of strength without having to put people at risk

• You can go all the way down and hold that bottom position for 30 seconds (this is challenging if you don’t have the right positioning) Andy would cap this when you break position (not when you get fatigued)

• Andy would cap this when you break position (not when you get fatigued)

• 2 minutes is excellent

• You don’t fail when you give up, but when you make a compensatory movement (shoot your butt out or lunge forward)
• This is a great test of strength without having to put people at risk

Additional training tips: movement patterns, how to finish a workout, and more [2:25:45]

Three major planes of movement

• There are three major planes of movement‒ frontal, sagittal, and transverse This means you need to be moving up and down, like a squat You need to be moving things away from and towards you, like a bench press And you also need to be moving things laterally, like a lateral lunge

• This means you need to be moving up and down, like a squat

• You need to be moving things away from and towards you, like a bench press
• And you also need to be moving things laterally, like a lateral lunge

“ It’s important that you’re moving in multiple planes ”‒ Andy Galpin

Other movement considerations

• You also need to include twisting and rotation
• The other thing you want to keep in mind is single leg versus either split stance or unilateral There is not perfect number to hit, just select something across those three days where you’re not doing everything supported by two feet For example, one-footed RDL , step-ups , split squats or rear foot elevated split squats , single-leg press, single-leg extension

• Don’t think you have to do everything using a barbell If it’s a movement with a rotation, maybe use a kettlebell Use a dumbbell for some movements and a machine for others

• There is not perfect number to hit, just select something across those three days where you’re not doing everything supported by two feet

• For example, one-footed RDL , step-ups , split squats or rear foot elevated split squats , single-leg press, single-leg extension

• If it’s a movement with a rotation, maybe use a kettlebell

• Use a dumbbell for some movements and a machine for others

For the hypothetical person who is beginning a strength training program

• This person is only six months into training; you don’t want their whole day being learning how to do a movement You also don’t want to stay on the machines the whole time
• You do want to invest a little bit into growth

• Spend 60% of time in what you need to be here, 20% in long-term development, and the other 20% is fun

• You also don’t want to stay on the machines the whole time

How to end your workout

• Andy recommends finishing every session with something that gets the heart rate close to its maximum or close to your personal pain point
• Peter always finishes with KAATSU , and there’s some intense pain The last two minutes of BFR (blood flow restriction) on the air bike combines two beautiful personal pieces of pain

• Andy recommends finishing by targeting “the thing you love to hate”, or an area you want to grow

• The last two minutes of BFR (blood flow restriction) on the air bike combines two beautiful personal pieces of pain

“ We’re going to finish the session with a triceps blast. We’re just going to smash it. ”‒ Andy Galpin

• Make sure in one of those days we touch high heart rate
• Peter thinks a classic way to touch high heart rate would be with at Tabata type exercise

Ways to incorporate high heart rate exercise into a workout plan [2:28:45]

What are some ways that you might recommend getting high heart rate exercise in, for this hypothetical person?

• You typically want to avoid eccentrics This is where CrossFit has done very poorly, putting people in a position of fatigue and very risky situations For other individuals, CrossFit can be fantastic
• Air bikes (work your arms and legs); rowers are also good
• You can do specific breath hold manipulation to alter CO 2 tolerance (CO 2 can get very high)
• In the pool, you can do a lot of stuff with weights underwater and just changing what you’re doing with ventilation and you can get to a level of pain very quickly that requires very little physical trauma
• Simple examples would be to do a ten-second sprint on the bike and then go into a breath hold

• You want to see your heart rate shoot up incredibly fast and then you’re going to come back out of that and you got 30 seconds, but you’re only going to use nasal recovery breath

• This is where CrossFit has done very poorly, putting people in a position of fatigue and very risky situations

• For other individuals, CrossFit can be fantastic

How long would you do a breath hold?

• The goal is your maximum
• Peter asks, “ In other words, go 10 seconds all out, breath hold until failure, 30 second recovery nasal only. How many rounds of that? ”
• Aim for three One might be the answer if you’re not even close to ready to do this again

• You can do an inhale-hold, breath-in-hold, and then hit that sprint

• One might be the answer if you’re not even close to ready to do this again

There’s a ton of ways you can play with CO 2 tolerance, and you’ll see your heart rate get up near maximum without much physical work

• Breath holds are a good way to get that fitness in if you need to spare your joints, spare soreness, spare energy

Looking toward part two of this podcast

• We went through one case study‒ they guy who never exercised
• We didn’t talk about much physiology, and Peter had 10 pages of notes on physiology that he wanted to talk about We got through half of the first page
• Plus Peter has a bunch of questions that we didn’t get to
• Hopefully in a couple months we can come back and have part two of this discussion
• Peter can’t wait to get into other case studies which are more his phenotype‒ “ I do exercise, but how do I take it to the next level? ”

• Andy can also speak to what professional athletes do for sleep, nutrition, training

• We got through half of the first page

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Background on this hypothetical person

• They were active in highschool and college, but over the last 10 years, their only exercise has been activities of daily living (hiking with the kids, etc.)
• They have started doing a couple of hours of week of zone II on the bike, but they don’t know how to approach strength training
• They are willing to put three hours a week in the gym, 1 hour at a time
• Their DEXA scan shows that their ALMI is about 40th%
• They want to aim for the 75% for lean mass (or above) in 2-3 years
• They want to gain functional strength for the purpose of longevity, and they want to add some muscle mass

General advice

• Begin with hypertrophy

• Spending time initially getting physically fit before trying to add muscle mass for someone like this is a very fruitful investment

• Start out with low volume, and be very cautious of eccentric movements (that will generate more soreness)

• Begin by building movement patterns that you will need over time (to prevent injury) Master the movement pattern before progressing the load

• Master the movement pattern before progressing the load

The first six months

• Continue zone 2 training, 2 hours per week
• Add three, one-hour sessions of strength training per week 1-3 working sets of 4 exercises a day, spread across both upper and lower body Practice compound movements

• Spend 30 minutes on these exercises Goblet squat, hip extension, and a basic overhead press (or some bent rows)

• 1-3 working sets of 4 exercises a day, spread across both upper and lower body

• Practice compound movements

• Goblet squat, hip extension, and a basic overhead press (or some bent rows)

The second six months

• In the first 10-15 minutes focus on power, speed, and agility; this will prevent injury and preserve function in old age Box jump (jump from the ground and land on an 18-inch box) If you do plyometrics, don’t do too many at high intensity (five minutes of jumping rope) 15-second intervals of sprinting at 70% effort with 1-2 minutes of rest Play racquetball or badminton Switch it up each day at the gym, using any of the above

• Next, move into strength training Keep a structure of total body workouts on all three days but vary the rep range Monday: 3-4 sets of 5-7 reps using heavier weights (aim for a RPE of 7-8; rest 1.5 minutes in between) Wednesday: 15-20 reps per set Friday: do something like isometrics where you’re just holding different positions

• Box jump (jump from the ground and land on an 18-inch box)

• If you do plyometrics, don’t do too many at high intensity (five minutes of jumping rope)
• 15-second intervals of sprinting at 70% effort with 1-2 minutes of rest
• Play racquetball or badminton

• Switch it up each day at the gym, using any of the above

• Keep a structure of total body workouts on all three days but vary the rep range

• Monday: 3-4 sets of 5-7 reps using heavier weights (aim for a RPE of 7-8; rest 1.5 minutes in between)
• Wednesday: 15-20 reps per set
• Friday: do something like isometrics where you’re just holding different positions

All three are equally effective for hypertrophy

• End the workout by targeting either the thing you hate doing or an area you want to grow

• At least one of these days, touch a high heart rate End each workout with two minutes of something that gets the heart rate close to its maximum (many options are discussed including breath holds)

• End each workout with two minutes of something that gets the heart rate close to its maximum (many options are discussed including breath holds)

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Selected Links / Related Material

Previous episodes of The Drive with Layne Norton :

• #163 – Layne Norton, Ph.D.: Building muscle, losing fat, and the importance of resistance training | Host Peter Attia, The Peter Attia Drive Podcast (May 24, 2021) | [9:45]
• #205 – Energy balance, nutrition, & building muscle | Layne Norton, Ph.D. (Pt.2) | Host Peter Attia, The Peter Attia Drive Podcast (May 2, 2022) | [9:45]
• #235 ‒ Training principles for mass and strength, changing views on nutrition, creatine supplementation, and more | Layne Norton, Ph.D. | Host Peter Attia, The Peter Attia Drive Podcast (December 19, 2022) | [9:45]

Muscle composition of Olympic weightlifters : Extraordinary fast-twitch fiber abundance in elite weightlifters | PLoS One (N Serrano et al. 2019) | [10:15, 1:01:15]

Previous episode of The Drive with Holly : #228 ‒ Improving body composition, female-specific training principles, and overcoming an eating disorder | Holly Baxter, APD | Host Peter Attia, The Peter Attia Drive Podcast (October 24, 2022) | [14:30, 1:59:45]

Andy’s YouTube video explaining a campfire analogy to understand energetics : Energy Systems – How The Body Uses Fat, Carbs, & Protein For Fuel: 5 Min Phys | Andy Galpin (March 13, 2018) | [20:45]

Andy’s twin study : Muscle health and performance in monozygotic twins with 30 years of discordant exercise habits | European Journal of Applied Physiology (KE Bathgate et al. 2018) | [1:02:30]

Andy’s study of life long skiers now over 80 years old : New records in aerobic power among octogenarian lifelong endurance athletes | Journal of Applied Physiology (S Trappe et al. 2013) | [1:07:00]

Case study of a record holder for the 60-m and 110-m hurdles : Skeletal muscle signature of a champion sprint runner | Journal of Applied Physiology (S Trappe eta l. 1985) | [1:25:15]

Andy’s Rapid Health Optimization program : Andy Galpin, PhD | [1:51:30]

Endurance exercise prior to strength training enhances hypertrophy : Short-term aerobic conditioning prior to resistance training augments muscle hypertrophy and satellite cell content in healthy young men and women | FASEB (A Thomas et al. 2022) | [1:53:00]

Changes in muscle fiber contractile function with aging : Single muscle fibre contractile function with aging | The Journal of Physiology (GJ Grosicki, CS Zepeda, & CW Sundberg 2022) | [1:55:00]

Humerus position plays a key role in muscle hypertrophy elicited from triceps extensions : Triceps brachii hypertrophy is substantially greater after elbow extension training performed in the overhead versus neutral arm position | European Journal of Sports Science (S Maeo et al. 2022) | [2:17:00]

Andy’s study on bands : Acute Effects of Elastic Bands on Kinetic Characteristics During the Deadlift at Moderate and Heavy Loads | Journal of Strength and Conditioning Research (A Galpin et al. 2015) | [2:21:00]

Position of triceps extension results in greater muscle mass : Triceps brachii hypertrophy is substantially greater after elbow extension training performed in the overhead versus neutral arm position | European Journal of Sports Science (S Maeo et al. 2022) | [2:17:00]

Andy’s book : Unplugged by Brian Mackenzie, Andy Galpin, and Phil White (July 11, 2017) |

Men’s Health Article about Andy’s research : How Scientists Are Learning How to Use Your Muscles to Predict Your Mortality | Lou Schuler, Men’s Health (June 21, 2019)

People Mentioned

• Layne Norton (Natural bodybuilder, powerlifter, physique coach, and author) [9:45, 14:00, 20:30, 48:00, 1:49:45]
• Holly Baxter (bodybuilder and accredited practicing dietician) [14:45, 1:59:46]
• Elwood Henneman (Neurophysiologist who characterized vertebrate motor neurons) [50:30]
• Dr. Kevorkian (Pathologist who championed physician-assisted suicide) [51:15]
• Jimmy Bagley (Assistant Professor of Kinesiology and Director of the Muscle Physiology Lab at San Francisco State University) [1:03:15]
• Michael Roberts (Professor of Kinesiology at Auburn University) [1:33:15]
• Jay Cutler (retired professional bodybuilder, four-time Mr. Olympia winner) [1:37:00]
• Frankie Edgar (retired mixed martial artist, 2010 UFC lightweight champion) [1:46:30]
• Greg Grosicki (Associate Professor of Health Sciences and Kinesiology) [1:55:00]

Andy Galpin earned his undergraduate degree in Exercise Science at Linfield College where he played football and won a DIII National Championship. He earned his Master’s degree in Human Movement Sciences from the University of Memphis and his Ph.D. in Human Bioenergetics from Ball State University. Andy is a Professor of Kinesiology at California State University, Fullerton where he is also the Director for the Center for Sport Performance. He is an active member of the National Strength and Conditioning Association & American College of Sports Medicine. He serves on the advisory board of many private and non-profit companies in the area of human performance. He is the author of the best-selling book Unplugged and routinely speaks at conferences, clinics, and podcasts around the globe. Andy also works as a high performance coach and consultant to numerous professional athletes (MMA, Boxing, Wrestling, BJJ, MLB, NFL, etc.). [ CSU Fullerton ]

Website: andygalpin.com

Instagram: drandygalpin

Twitter: @DrAndyGalpin