Dr. Andy Galpin: Optimal Protocols to Build Strength & Grow Muscles

High-Level Overview

In the second episode of his six-part series with Andrew Huberman, Dr. Andy Galpin, professor of kinesiology at Cal State Fullerton, turns from theory to the gym floor. The subject is how to get stronger, faster, more powerful and more muscular, and why those are related but separate goals. Galpin opens with the case for strength training at every age, walks through what actually changes in nerves, muscle fibers, tendons and bones when we get stronger or bigger, and then spends the bulk of the conversation laying out concrete programs: the "three to five" system for speed, power and strength, and a far more forgiving framework for hypertrophy built around weekly sets per muscle group.

The tone is technical but playful. Galpin dives into acetylcholine recycling, actin-myosin lattice spacing and myonuclei, while Huberman keeps pulling the discussion back to practical questions (warm-ups, rep cadence, breathing, failure, splits, cold plunges, protein and creatine) and trades jokes with his guest about kettlebells, neck bridges and Galpin's ice-filled deep freezer. The conversation swings between muscle physiology, coaching stories from elite athletes, and step-by-step programming advice, closing with a quick round on recovery, nutrition and supplements.

The Discussion Explores:

• Why strength training is the main tool against neuromuscular aging, and why strength and power fade faster than muscle size
• How strength (a function) differs from hypertrophy (a size change), and the many adaptations behind each
• The newest science on muscle growth, including sarcoplasmic hypertrophy and the epigenetic basis of "muscle memory"
• The non-negotiable concepts of any program versus the modifiable variables that decide what adaptation you get
• The "three to five" approach to speed, power and strength, plus warm-ups, cadence, breathing, cluster sets and banded training
• Hypertrophy programming: 10 to 20 weekly sets, rep ranges from about 4 to 30, proximity to failure, rest periods and splits
• Recovery signals, cardio interference, and whether cold exposure blunts muscle growth
• Protein targets, carbohydrate timing and creatine as the one supplement worth taking

Deep Dive into Main Ideas

Strength training as the frontline defense against aging

Galpin begins by attacking what he calls one of the field's big disservices: the idea that strength training is for athletes and bodybuilders while cardio is for heart health and fat loss. His central claim is that "resistance exercise and strength training is the number one tool to combat neuro muscular aging," and that no other form of exercise delivers it. Movement requires nerves to fire, muscles to contract and those muscles to move bones, and losing any link in that chain threatens independence later in life.

He gives the numbers that frame the whole episode. People lose roughly 1% of muscle size per year after about age 40, but 2 to 4% of strength per year and something like 8 to 10% of power per year. Older adults can show a 30 to 40% reduction in motor units. The practical problem of aging, then, is less about keeping muscle and more about keeping the strength and power that let you stand up, catch a fall and move with confidence. Huberman adds Sherrington's idea that movement is the final common path and the link between loaded movement and a healthy brain.

The encouraging part is that it is never too late. Galpin describes a study of people over 90 who saw improvements of 30 to 170% in muscle measures in about 12 weeks, and newer data suggesting that most age-related loss of strength comes from a loss of training (along with nutrition and anabolic resistance) rather than some unavoidable biological decline. He also argues that strength work is unusually motivating because results show up fast, often visibly within four to six weeks, and adherence is the single strongest predictor of whether any program works.

Strength versus hypertrophy, tendons and bone

Strength is a function, the ability to produce force; hypertrophy is simply an increase in size. The two overlap heavily in beginners but separate with experience. Galpin's example is powerlifters versus bodybuilders: both are strong and muscular, but powerlifters are clearly stronger and bodybuilders clearly bigger. Weight classes in strength sports show that you can get stronger without adding mass, up to a point. He splits strength into physiology (the ability of the neuromuscular system and fibers to produce force) and mechanics (limb lengths, technique, skill and sequencing).

Connective tissue adapts too, but slowly, because it lacks the blood supply and plasticity of muscle, which Galpin calls perhaps the most plastic organ in the body and the largest organ system, constantly signaling to the immune system, blood glucose regulation and amino acid supply. Tendon and ligament adaptation is a major reason strength training reduces injury, and a lack of "tissue tolerance" is why returning weekend athletes tear things. On bone, Huberman shares Eric Kandel's lab finding that load-bearing exercise releases osteocalcin, which supports memory. Galpin confirms that bone strengthens with training, especially under axial loading and most strongly in the teens and 20s, and describes women in his program seeing measurable bone density gains within eight months, usually alongside nutrition and hormonal work-ups such as 30-day salivary tracking across the menstrual cycle.

What changes inside you when you get stronger or bigger

Galpin walks through the chain from nerve to bone. Training improves motor unit firing rate and synchronization, acetylcholine release and recycling at the neuromuscular junction, calcium handling by the sarcoplasmic reticulum, and the strength of the actin-myosin cross-bridge. Fibers can shift from slow-twitch to fast-twitch, pennation angles change the trade-off between force and velocity, and phosphocreatine storage increases. All of this explains how someone can get stronger without getting bigger. Conversely, growing muscle can slightly disturb the lattice spacing between actin and myosin, which is why size does not always translate into strength.

For hypertrophy, the core is muscle protein synthesis. A signal at the cell (stretch, amino acids, hormones) triggers a signaling cascade, gene expression and protein building. Eating about 30 grams of protein alone measurably raises protein synthesis for several hours even without lifting, lifting alone does the same, and the two stack. Endurance work runs through a different pathway (AMPK, driving mitochondrial growth rather than mTOR-driven protein synthesis), which is the first molecular explanation for the "interference effect." Galpin also stresses that muscle protein turnover matters for immune function, autophagy and repair, not just bigger muscles.

New science: sarcoplasmic hypertrophy and muscle memory

Galpin highlights how quickly this field is changing. Sarcoplasmic hypertrophy, once dismissed as "bro science," now looks real, thanks to work by Mike Roberts at Auburn: some growth comes from increased fluid in the fiber rather than more contractile protein, which helps explain why a muscle can get bigger without getting stronger. Muscle is also unusual in having thousands of nuclei per cell, supplied by satellite cells, and researchers long believed that retained nuclei explain why regaining lost muscle is faster than building it the first time.

Galpin says that explanation now looks wrong, including things he has said on earlier podcasts. The newer view, from a paper he just submitted with Jimmy Bagley and Kevin Murach, is that the change is epigenetic: in his words, "the nuclei are remembering how to ride a bike." Different nuclei may also specialize, with some clustered around mitochondria and others devoted to repair, which could explain individual differences in recovery. His reassurance is that while the mechanisms keep shifting, what to do in the gym has been well established for a long time.

The concepts that every program needs

Before any protocol, Galpin lists the non-negotiables. First is adherence; he quotes collaborator Dan Garner that "consistency beats intensity." Second is progressive overload, which he calls the most common reason people fail to reach their goals after simply not training. Third is individualization around preferences, equipment and schedule, and fourth is picking the right target, ideally informed by the fitness tests from episode one. On top of these sits the balance between specificity (enough stimulus on the target) and variation (enough change to avoid overuse injuries).

The key reframe is that "exercises do not determine adaptation"; how you execute them does. A deadlift will not build strength unless it is loaded and performed correctly, and a box jump will not build power unless you do it explosively. The modifiable variables he uses throughout are exercise choice, order, volume, intensity, rest, frequency and progression. Huberman also recaps the nine adaptations from episode one: skill, speed, power, strength, hypertrophy, muscular endurance, anaerobic capacity, maximal aerobic capacity and long-duration steady-state endurance.

The "three to five" system for speed, power and strength

For speed, power and strength, Galpin recommends three to five days per week, three to five exercises, three to five reps per set, three to five sets and three to five minutes of rest. That spans a minimal plan of three sets of three on three exercises three days a week up to five by five by five. Singles and doubles are fine; more than five reps per set generally is not. Load decides the adaptation: roughly 30 to 70% of your one-rep max, moved with maximal intent, trains power (closer to 30 to 40% on a bench press, 50 to 60% on a squat), while strength needs at least 70%, with some work above 90%. Intent is critical: "You don't get faster by moving kind of fast." Progress by about 3 to 5% per week in load, and up to about 5% per week in volume, for about five and at most eight weeks before a deload.

Choose compound movements selected by movement pattern (push, pull, hinge or squat, and rotation, such as a cable rotational pull or medicine ball throws) and do them first, when you are fresh, because fatigue here only teaches you to be slower. Power work is not fatiguing, so extra hypertrophy or conditioning afterward is fine, though for serious strength goals it can cost some recovery. Galpin compares linear periodization (one adaptation per six to eight week block) with undulating periodization (several in a week or even a day): studies find them about equally effective, and the choice is a trade-off between focus and losing other qualities. He also urges people to plan in six to 12 week blocks rather than day to day.

He adds several tools. The Prilipin chart (from powerlifting and weightlifting) guides how many reps to accumulate in each intensity zone, with roughly seven total reps per session above 90%. The Bulgarian method shows how far pure specificity can go and what it costs athletes. Autoregulation adjusts the day's loads to how you perform that day, for example with bar velocity. Cluster sets, resting 5 to 20 seconds between single reps, keep every rep as good as the first. Eccentric overload, lowering more than your one-rep max with spotters, is an advanced option. Dynamic variable resistance with bands or chains matches load to the strength curve. Supersetting saves time; a study in Galpin's lab found some loss of strength gains, a trade most people would take. He also points to intent: a plank or a light weight contracted as hard as possible can still build strength.

Warm-ups, rep cadence, breathing and training to failure

Warm-ups are highly individual. Galpin tells the story of an elite pitcher whose vertical jump peaked on about rep 70 and who kept jumping past rep 130, while other people fatigue after two or three reps. The guiding rule: "volume is the primary driver in hypertrophy. Intensity is the primary driver in speed power and strength." For strength and power, warm up until you are truly at peak. For hypertrophy, do not let the warm-up eat into your working volume. He prefers five to seven minutes of dynamic, whole-body movement over static stretching or stationary cycling, followed by specific warm-up sets for the first and most complex exercise, and extra ones only for dissimilar or skill-heavy lifts later on.

For cadence, strength rests on force equals mass times acceleration, so deliberately moving slowly only lowers acceleration. A 3-1-1 tempo (three-second eccentric, brief controlled pause, explosive concentric) is a solid default; 3-1-2 works for hypertrophy, where cadence matters less and slower reps, triphasic training (eccentric, isometric, then concentric phases) or 10-second hotel-room reps can make up for light loads. On breathing, Galpin explains the Valsalva brace: fill the abdomen in all directions rather than lifting the collarbones, add muscular bracing, and ideally learn to stay braced while talking. Blood pressure can spike as high as 450 over 350 during very heavy sets, which is what causes blackouts. For heavy singles or doubles, breathe in before the eccentric and hold; for long sets, use planned breathing patterns, like the ones he teaches NFL combine athletes for the 225-pound bench test, and only take a new breath at lockout.

Failure is not required for strength. Technical failure is usually enough, though Galpin likes taking novices to a true max now and then so they learn what 100% means, safely and ideally with a spotter; he warns against benching alone. He also explains why Huberman needs days to recover: training in the 4 to 12 rep range to failure is the most soreness-inducing style, while athletes who train with lower volume and more rest can hit the same muscles daily. For beginners, keep the same exercises for at least six weeks, and up to 10 to 12, since it takes about three weeks just to find the groove. Powerlifters in the conjugate system make only small weekly variations to the same lifts.

Hypertrophy: an "idiot proof" framework

Galpin calls hypertrophy programming forgiving: "it's kind of idiot proof." Growth can come through mechanical tension, metabolic stress (which is why blood flow restriction at 20 to 30% of max works) or muscle damage, and he stresses that "it's a flat out lie that you have to break a muscle down to cause it to grow." The signal has to be either loud enough or frequent enough; the only combination that fails is low frequency, low intensity and low volume. You can choose exercises by muscle or by movement pattern, should mix bilateral and unilateral work, and should appreciate machines, especially since individual anatomy means a squat or bench press may not load the muscle you expect. High-bar and low-bar squats, for example, shift work between the quads and the glutes and lower back. Order is flexible, including pre-fatiguing a target muscle with an isolation exercise.

Volume is the main driver: at least 10 hard working sets per muscle group per week, more realistically 15 to 20, and perhaps around 25 for well-trained people. Count a set toward a muscle if it is a primary or secondary mover (biceps in a chin-up yes, in a pull-up probably not), and train rear delts and hamstrings directly. Reps can run from about 4 to 30 as long as sets end within about two reps of failure; 8 to 15 is the sweet spot, and 5 to 8 (or the no-man's-land range of 7 to 9) blends strength and size. Save true failure for safer machine or single-joint exercises or the last exercise of the day, a point Galpin credits to a review from Eric Helms's team. Rest can be as long as three to five minutes if load or volume is kept up, though two minutes is practical. For people who want strength without size, he suggests low reps, such as eight sets of three, modest calorie intake and infrequent training.

On splits, Galpin prefers three full-body days a week for most people. It is not that frequency matters much in the research, but it is more resilient when life gets in the way. He warns that "legs are many muscle groups and should not get one day against four upper-body days. Waiting 48 to 72 hours between sessions for a muscle is reasonable, and there is no loss in five to seven days as long as weekly volume is met. Plateaus and non-responders" usually need a different stimulus, often more volume or a shift to heavier or much higher-rep work. Galpin would not use Olympic lifts or plyometrics for hypertrophy. When Huberman asks whether to skip an easily grown muscle, Galpin advises keeping low volume on big compound lifts for balance, motor patterns and joint health. For the neck he recommends isometrics over neck bridges, and he points listeners to coach Eric Cressey's resources for shoulder and rear-delt work.

Recovery, cardio, cold, protein and creatine

For judging recovery, Galpin uses a subjective soreness scale: above three out of ten raises questions, and above six means no training that day. For chronic problems, his team checks blood markers such as creatine kinase, LDH, myoglobin and the AST-to-ALT ratio, plus sleep, heart rate variability, resting heart rate trends over three to five days, and motivation. On a bad day during a hypertrophy phase, he would rather do light, easy volume than cancel the session. Cardio interferes with hypertrophy mainly through low energy intake and eccentric-heavy modes like running, so cycling is kinder than running, and separate days or sessions are best. High-intensity intervals may even help, and one recent study found that six weeks of endurance training before a hypertrophy phase led to more muscle growth.

Cold plunges are a clear no around hypertrophy work: Galpin says ice exposure blocks the growth signal and should not come immediately after, before, or even on the same day as a hypertrophy session. It is fine in-season or during phases where recovery is the priority, and cold showers are generally not a problem. On protein, he endorses Layne Norton's range of about 1.6 to 2.2 grams per kilogram (roughly one gram per pound), noting that at high enough intake, timing, source and quality matter much less, which Stu Phillips's work on non-animal proteins supports. Carbohydrate timing does matter: about a 1:1 carbohydrate-to-protein ratio around strength work (for example 35 grams of each), about 2:1 for mixed sessions and 3:1 or 4:1 after hard conditioning. His one supplement pick: "creatine is the answer here without question." He recommends creatine monohydrate at about 3 to 6 grams per day (5 grams as the standard, scaled up for very large athletes), taken at any time of day.

Conclusion

Galpin's core message is that the concepts are few and the methods are many. Stay consistent, overload progressively, individualize, and aim at the right target, then let the modifiable variables decide whether you build power, strength or size. Speed, power and strength reward low reps, heavy or fast loads, long rests and total focus, captured in the simple "three to five" rule. Hypertrophy is far more forgiving, as long as you pile up roughly 10 to 20 hard weekly sets per muscle close to failure and support them with food, sleep and recovery. Behind the programming is a strong case that everyone, at any age, should train for strength and power, because those are what we lose fastest, and the science of how muscle adapts is still being rewritten almost every year.

This is a summary of "Dr. Andy Galpin: Optimal Protocols to Build Strength & Grow Muscles" from Huberman Lab, giving you the GIST so you can decide if you want the REST. Listen to the full episode.