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#163 – Layne Norton, Ph.D. : Building Muscle, Losing Fat, And The Importance Of Resistance Training| The Drive With Peter Attia


Layne Norton, Ph.D. (@BioLayne), is a physique coach, natural professional bodybuilder, and powerlifter. He holds a Ph.D. in Nutrition Science and is a world-renowned expert on fat loss and maintaining muscle while losing fat.

In this episode of The Drive, Peter sits down with Dr. Layne Norton to discuss how to prevent and manage injuries, the science of body composition and muscle growth, the role of nutrition, supplements and hormones, and the keys to developing healthy habits.

Host: Peter Attia (@PeterAttiaMD)

Book: Fat Loss Forever by Layne Norton, Ph.D.

Key takeaways

  • “Resistance training is the most powerful tool to change body composition and arguably overall health too.” – Layne Norton
  • As you approach lower levels of body fat, spend more time in maintenance than deficit
  • The benefits of fasting really depend on your goals: if you are looking to maintain your current muscle mass, incorporate fasting; if you are looking to maximize lifts, PR and build strength – reconsider
  • Metabolism is not an on/off switch: you are always burning and storing fat simultaneously – and – synthesizing and degrading protein at the same time
  • We need to look at things mechanistically: nutrients and hormones are not exclusively good or bad – we have to look at the context
  • The most powerful predictor of longevity past age 65 is how much lean body mass you have
  • It’s not impossible – but – it may be tougher to build muscle on a ketogenic diet because carbohydrates blunt muscle breakdown
  • Consistency in exercise and nutrition partly requires forming a new identity: instead of “I run” – think, “I am a runner”
  • You don’t have to be motivated to exercise or eat well – make it part of what you do and who you are to maintain consistency
  • Ask yourself how you can get better, not how you can be like someone else

Layne’s Background And Intro To Lifting

  • Layne wasn’t naturally gifted in any sport and struggled with ADHD throughout childhood
  • Started lifting weights so he would get picked on less and land some dates
  • Didn’t come from an area that was a hotbed for lifting so literally went to the library to read books and understand periodization and how to lift
  • Lifting didn’t come naturally – wasn’t a hyper muscle grower
  • Layne enjoyed the fairness of lifting: the level of work you get in is what you see and the black and white nature of measurability
  • Entered his first contest at age 19 and won but really attributes success to stubbornness and ability to tolerate high training volume
  • Layne has always remained drug-free throughout his lifting career – no steroids or anabolic hormones

Signal To Noise In The Fitness Industry

  • Dunn-Kruger curve: when learning a topic, perceived knowledge skyrockets in 6-12 month; as you keep learning, perceived knowledge goes down and actual knowledge goes up
  • “Once you drink from the fountain of knowledge you will thirst for the ignorance you once had.” Layne Norton quoting mentor
  • Constantly look for examples that contradict your belief system
  • Social media creates people that shout loudly when perceived knowledge is high but actual knowledge isn’t necessarily  
  • The signal to noise ratio on nutrition and fitness is difficult to navigate – we tend to default to whatever our bias is

Training Versus Nutrition

  • “Resistance training is the most powerful tool to change body composition and arguably overall health too.” – Layne Norton
  • “Training is the most powerful thing for your health and body composition that you can do.” – Layne Norton
  • You can have a clean diet, eat tons of protein, etc. but without training, the changes to body composition will be minimal
  • Start small! Just start showing up and build confidence in exercise then increase weights over time

Working With Pain

  • Layne had several herniated discs in his back from old rugby injuries
  • Resistance training is one of the best things you can do for low back pain
  • Potential root of back pain when lifting: (1) can’t generate enough intra-abdominal pressure; (2) can’t generate enough segmental control in the spine so load at hinge points is inadequate
  • Stress & lack of sleep play a role in pain sensitivity
  • The biopsychosocial model of pain is murky: you can have tissue damage and no pain or very little tissue damage and high pain
  • We tend to push through the pain but working with a load that increases pain will make it worse
  • If you have pain: modify load, tempo, range of motion, exercise selection – to see if the pain is reduced
  • Example of steps to work through injury or pain during a squat: (1) reduce range of motion; (2) work at a slower tempo and reduced range of motion; (3) make small, gradual increases to the range of motion until full quat achieved

Tradeoffs Between Powerlifting And Bodybuilding Competition

  • Bodybuilding is subjective and more focused on appearance than strength
  • Powerlifting requires strength and isn’t worried about aesthetics
  • Overlap: to look muscular you have to have a lot of muscle
  • Hypertrophy matters for strength training: the more muscle you have, the more you can lift
  • There’s a lot of ways to skin the cat in bodybuilding: doesn’t matter what exercise you do as long as you do enough
  • Bodybuilding is more forgiving because you just need to create tension, volume, and progressive overload – if you don’t like an exercise, you can do something else
  • You have no choice but to perform major lifts for powerlifting
  • Bodybuilding is more mentally demanding – bodybuilders go through periods of extreme hunger and low energy

Lean Body Mass

  • Lean body mass is not the same thing as muscle mass
  • Lean body mass: all nonfat tissue – skin, bone, water, organ weight, etc.
  • The volume of lean body mass loss will vary depending on how much body fat you carry naturally
  • As you exit the lower end of body fat setpoint, you will likely pull more from lean body mass as opposed to fat tissue
    • One method to overcome: resistance training
  • If you are overweight or obese you don’t have to worry about losing lean body mass because you have a reservoir of energy to pull from so a body won’t draw from lean body mass
  • To go from 15% body fat to 7% body fat will usually cause less lean body mass loss than going from 7% to 5% body fat
  • When trying to shed that last bit of fat, you might lose just as much lean body mass as fat loss  
  • Tip: as you approach lower levels of body fat, try diet breaks – periods of eating at maintenance where you won’t add fat but can eat more than you did previously
    • Diet aggressively 2-3 weeks then take 1-2 weeks and eat at caloric maintenance
    • In other words, spend more time at maintenance than deficit

Fasting And Its Impact On Fat And Muscle

  • Peter’s observations on 5-7 day water fast: as long as he’s resistance training daily, he needed more rest between sets but could move the same amounts of weights and didn’t lose muscle mass
  • Once you’ve built it, the work to maintain contractile tissue (muscle) is fairly minimal
  • You can build strength and maintain it during periods of fasting
  • If your goal is to be the most muscular, strongest person – fasting isn’t for you

Plant Versus Animal Protein

  • You can build muscle with plant protein but it will require a bit more planning and attention to detail because of leucine and amino acid composition
  • Animal protein is the superior source of protein – BUT – it’s a small sliver of what contributes to hypertrophy
    • Consistent resistance training and progressive overload is by far more important
  • Studies on animal versus plant protein are limiting (not bad studies) because trials are usually only 8-12 weeks
  • The more you put limits on studies, the shorter the study becomes and less you can extract in real-world settings
    • Animal studies are really the only way to have tightly controlled, long studies
  • Questions we don’t necessarily have answers to: does the timing of protein intake matter? Does timing in relation to training matter? Does training timing matter?
  • We need to look at eating patterns more than we look at individual nutrients

Muscle Protein Synthesis & Importance of Leucine

  • People falsely think of metabolism as an on/off switch
  • Muscle protein synthesis is the synthesis of muscle proteins from amino acid substrates
  • Protein synthesis starts in DNA because DNA codes for proteins that will be synthesized
  • Very broadly: resistance training triggers a cascade of DNA response to a stressor and brings amino acids in to build new proteins
  • Around 7 out of every 8 amino acids are recycled from degraded proteins
  • Muscle tissue is about 70% water and 30% protein
  • Purified solutions of leucine increase mTor activity and muscle protein synthesis
  • Whey protein increases and peaks muscle protein synthesis at 90-minutes post-meal then goes back down to by baseline by 3 hrs
  • In mixed muscle protein synthesis: the peak is about the same for untrained versus untrained but the duration of peak lasts longer in untrained
    • Mixed muscle protein includes cytoplasmic proteins, mitochondrial proteins, etc.
  • In myofibrillar (contractile) muscle protein synthesis: don’t know how long it lasts for trained or untrained
  • A nuance of protein degradation: don’t see much hypertrophy during the first 6 weeks of resistance training – you see strength improvement but not hypertrophy
  • Initial phases of training have a robust increase in muscle increase and protein degradation
  • After initial six weeks, degradation goes down and seems to coincide with improvements in hypertrophy

Hormonal Regulation On Muscle

  • Categories of hormone signaling:
    • Endocrine function: hormone released and effect is throughout the body (e.g., insulin)
    • Paracrine: hormone is released and only impacts cells next to it
    • Autocrine: hormone is released and only acts on itself
  • Must understand the difference between localized response versus systemic response and acute response versus chronic response
  • When we’re talking about hormones we’re seeing a summation of signals – it’s not just one hormone driving the surface outcome
    • For example, insulin is just one input to the whole picture
  • Testosterone in the cell is converted and binds to the androgen receptor, ramping capacity for many things including increasing muscle capacity
  • Leucine in the cell is a short term signal
  • When enough testosterone is available, androgen receptors upregulate to meet the demand to metabolize testosterone
  • Regulation of excess testosterone functions on luteinizing hormones and gonads
  • Muscle growth appears to be mostly intrinsically regulated
  • There has to be a translation of contractile force into a chemical signal
  • Growth hormone increases in response to exercise, fasting, resistance training, sleep
  • Growth hormone increases liver production of IGF1 – which was once considered master hormone tied to increased muscle mass
  • Growth hormone is not anabolic
  • IGF1 is the integral of growth hormone – you can get some understanding of how much growth hormone is around by measuring IGF1 in liver
  • IGF1 released by the muscle itself is also known as a mechano-growth factor – very anabolic to muscle tissue but is a localized response
  • Muscle tissue is energetically expensive to maintain

Anatomy Of Muscle & Muscle Building

  • Sarcomere: contractile unit of a muscle tissue
  • Z disc: lateral borders of sarcomere
  • Actin and myosin are proteins in the muscle that work together to generate contractions and movement
  • Phosphatidic acid: stored in Z disc and stimulates mTor – likely a more major regulator of mechano-transduction
  • Carbohydrate ingestion isn’t really linked to increases in muscle synthesis but does seem to inhibit protein degradation
  • Perhaps consuming the combination of carbohydrate and protein post-training could reduce degradation and increase synthesis but more studies need to be done
  • It may be tougher (not impossible but tougher) to build muscle on a ketogenic diet because of the crucial carbohydrate effect on blunting muscle breakdown
  • A ketogenic diet is difficult to study because of the length it takes the body to adapt
    • On a strict ketogenic diet, it took Peter 18 months to be able to resume full anaerobic exercise
  • There’s a difference between optimizing and “can you do it” – you can build muscle on keto – but would you have gained more if you were consuming carbs?

Cortisol & Relationship To Muscle

  • Nutrients are not good or bad – context matters
  • Cortisol is a long term hormone
  • Body used to release cortisol to trigger response to an emergency situation
  • Cortisol is most closely related to hypertrophy – the question is whether the cortisol is produced in response to stress or hypertrophy is taking place because cortisol is released
  • Resistance training produces stress which releases cortisol and eventually adaptation and eventually the hypertrophy if repeated
  • Cortisol alone also impedes muscle protein synthesis


  • It’s not too difficult to maintain muscle mass over time but does require some level of consistency
  • Consistency partly requires forming a new identity: instead of “I run” – think, “I am a runner”
  • Put in your mind that this is what you do and part of who you are
  • “The great thing about nutrition is you get to pick what you sacrifice. Pick the form of restriction that feels easiest to you.” – Layne Norton
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