Dr. Andrew Huberman, Ph.D. is a Professor of Neurobiology and Ophthalmology at Stanford University School of Medicine. His lab focuses on neural regeneration, neuroplasticity, and brain states such as stress, focus, fear, and optimal performance.
In this this episode of Huberman Lab, Dr. Huberman take a deep dive into muscles. He covers how brain and nervous system control movement, how to leverage systems of the body for muscle maintenance, muscle growth and recovery, protocols to increase muscle growth, and much more.
Host: Andrew Huberman (@hubermanlab)
Muscles are essential for maintaining how we breathe, how we move, metabolism, and posture
  • Posture is vital for alertness, how we breathe, how we move
Movement is directed by the relationship between neurons and connection to the muscle
The more muscle you have, the higher your metabolism
Jumping ability and ability to stand up quickly is one of the most predictive markers of aging
Much of the brain is devoted to vision and movement
The nervous system controls muscle through three areas of control: upper motor neurons, lower motor neurons, central pattern generators
Upper motor neurons: send signals to the spinal cord to direct activity to muscles
Lower motor neurons: send axons to muscles and cause contraction through acetylcholine
Central pattern generators: rhythmic, reflexive movements
You can use your nervous system to trigger hypertrophy (muscle growth)
Muscles function on glycolysis, the breakdown of glycogen and glucose into energy
Glucose and glycogen breakdown into pyruvate – in the presence of oxygen (in the muscle), more energy will be generated
Muscle is metabolically demanding
Humans make lactate, not lactic acid
Lactate has three functions: (1) buffer against muscle acidity; (2) fuel to generate muscular contractions in the absence of oxygen; (3) acts as hormonal signal (can influence tissue outside the body)
  • 10% of the time you should exercise to lactic threshold (when you feel the burn) to enhance function of organs
Benefits of lactate are only in the presence of oxygen so breathing is critical when you reach the point of burn
Exercise is beneficial for your brain and nervous system through hormonal signals (not increasing neuron)
Three ways muscles can be stimulated to change: (1) stress; (2) tension; (3) damage
Something needs to happen to force muscle tissue to change
Muscles get bigger as myosin (protein) gets thicker
Muscles can get stronger without getting bigger – however, increasing the size of the muscle almost inevitably increases strength
Muscles get weaker across the lifespan
Resistance exercise is important to offset the normal decline in strength and posture to generate a greater range of motion
Hanuman principle: recruit motor units from lowest to the highest threshold – in other words, use the minimum amount of energy required to move the object
The more efficient you are in recruiting motor units, the more you will stimulate muscle growth and strength
Everyone has imbalances in how muscles grow
The better you are at contracting and isolating muscles, the faster you will get desired effects
  • Try sending a signal to a muscle with your brain and contracting as hard as you can
You don’t necessarily need heavy-weights to grow muscles
For hypertrophy: move progressively greater loads, generate localized contraction of muscle, isolate muscle contractions
Move weights or use bands in 30-80% of 1RM (1 rep max)
Lifting in 75-80% range: bias improvements toward strength gains
Lifting in 30% range: bias towards hypertrophy and muscle endurance
For untrained individuals/beginners: perform enough sets of a given exercise per muscle each week
Range of sets to do to improve strength ranges from 2-20 sets per week depending on experience
Approximately 5 sets per week (at 30-80% 1RM) is required to maintain muscle
The exact number of sets depends on the intensity
10% of workouts should be reserved for working to muscle failure (or when form fails)
The majority of exercise should be dedicated to more volume without fatiguing the nervous system
Perform 5-15 sets per week, per muscle in 30-80% of 1RM
In general, keep resistance sessions to 45-60 min before cortisol and inflammatory pathways kick in
If you are a seasoned trainer: increase the number of sets per week so you hit closer to 25-30 sets per week
Always work within the full range of motion
To increase explosiveness and speed: move weights as fast as you can (safely) to increase neurons
  • Dedicate resistance training to jumping higher, running faster, throwing farther, etc – learn to generate force with increasing speed
  • Work within 60-70% and work as fast as you can with good form
To get stronger: slowing down weight and increasing time under tension (slow tempo) will isolate the muscle and encourage hypertrophy
For hypertrophy and strength gains, resting 2-5 minutes is the sweet spot
Change regimen over time: nervous system changes quickly at the beginning of training but slows over time
Pro tip to increase hypertrophy: flex muscles between sets about 30 seconds to improve stress, tension, and damage – this is good for hypertrophy not the performance and improving strength because you are fatiguing the muscle
An increase in testosterone is mediated by nerve the muscle connection
Fine line for increasing testosterone before cortisol kicks in takes over
Testosterone will increase with exercise lasting around 60 minutes; exercise past 75 minutes will drop testosterone and increase cortisol
Ideal training protocol to stimulate testosterone release: 6 sets of 10 repetitions with 120-sec rest between reps
Assess systemic recovery through three main tests: (1) heart rate variability; (2) test grip strength in the morning (before anything else); (3) test carbon dioxide tolerance in the morning (before anything else)
Heart rate variability: you don’t want a heart rate that is high or low – you want a mix
  • You can measure through a wearable device now – a watch, ring, bracelet
Grip strength: ability to generate force at the level of squeezing the fist
  • If you see a drop in grip strength ability, muscles are still rewiring to generate force and maybe fatigued
Carbon dioxide tolerance is an indicator of whether the system as a whole is working properly and measures your ability to mechanically control the diaphragm
  • Step 1: Inhale through the nose and exhale all the way – repeat 4x
  • Step 2: Take the 5th inhale as deep as you can, release as slowly as possible and time
  • Step 3: Stop the timer when you can no longer exhale anymore air
  • If carbon dioxide discard time is 20-25 seconds or less, you may need to rest
  • If discard times drop over time, you are veering in the direction of not recovering
Cold (cold plunge or ice bath) after resistance training seems to short circuit some of the benefits of training: reduces inflammation and muscle soreness – but does seem to interfere with mTor pathways
Anti-histamines appear to disrupt some of the beneficial inflammatory effects that occur during resistance training
Omega -3 and magnesium malate assist with delayed onset muscle soreness
Tips to improve strength training performance: (1) salt & electrolytes; (2) creatine; (3) beta-alanine
Salt – nerve cells communicate via electricity
The amount of salt needed will depend on water intake, caffeine intake, training load
Creatine – fuel source for high-intensity activity and has cognitive-enhancing effects in the brain
Daily creatine dose: 5g/day for 180lbs; 1-3g/day under 180lbs
Beta-alanine: supports the exercise of longer duration and mixed aerobic/anaerobic exercise (e.g., intervals, sprints)
Tips to improve endurance training performance: (1) beet juice; (2) citrulline; (3) arginine
Ingest 700-3,000mg or amino acid leucine from high-quality proteins
Consider protein density: it’s easier to get higher doses of nutrition and amino acids through meat & animal protein consumption versus a plant-based diet
Eat 2-4 meals per day to support muscle growth and repair
Hard bouts of exercise to near failure for 30-60 minutes reduces oxygenation in the brain temporarily
Control duration and intensity of exercise depending on the need to perform cognitive work
Body and nervous system predict bouts of intense exercise: stick to a training schedule and body clock will learn and adapt
Time of day for training doesn’t matter for hypertrophy but train for optimization with the sleep schedule
For more information, Dr. Huberman suggests checking out: Human Performance Education by Dr. Andy Galpin