Essentials: How to Build Strength, Muscle Size & Endurance | Dr. Andy Galpin

This Essentials episode opens with Andrew Huberman introducing Andy Galpin as one of "about three or four people" in exercise physiology whose advice leads him to change his own protocols. He asks Galpin to set out the principles of strength training, hypertrophy, power and the other training categories.

Galpin answers with a taxonomy of roughly nine adaptations that exercise can produce. The list starts with skill, meaning moving "mechanically how you want your body to move". Then come speed, power, strength and hypertrophy. He links power directly to the two qualities on either side of it: "if you actually multiply strength by speed, you get power."

The endurance-based adaptations, as Galpin describes them: muscular endurance (for example, how many pushups in one minute); anaerobic power (producing a lot of work for about 30 seconds to one or two minutes); a VO2 max-related capacity over roughly three to 12 minutes; and long-duration endurance, meaning sustained work of 30-plus minutes with no break, where duration matters rather than speed.

He stresses that these goals are not all compatible. Some carry over to each other, but others are "a little bit contrarian to the other ones," so pushing toward one may cost something elsewhere. This is the premise behind the rest of the conversation: training variables have to be tuned to the outcome you want.

Galpin's first universal rule is progressive overload. His reasoning is physiological: "Adaptation physiologically happens as a byproduct of stress." Doing the same workout over and over can maintain fitness, but "you better not expect much improvement." Overload can come from more weight, more repetitions, more sessions per week, or more complex movements. A fixed Monday-Wednesday-Saturday routine repeated "infinitely" won't get you very far.

So there's a lot of different ways to progress, but you have to have some sort of movement forward.

When Huberman asks which overload principles matter most for strength and hypertrophy, Galpin lays out a short list of "modifiable variables": the parts of a workout that, if changed, change the result. The first is exercise choice. He immediately qualifies its importance, though. Choosing the bench press does not make a workout strength training if the sets, reps or speed are wrong. In that case you "maybe get muscular endurance and very little strength adaptation." How you apply the exercise is the "primary determinant."

The variables as defined in the episode: choice (which exercise); intensity, which here means "quite literally" a percentage of one-rep max, maximum heart rate or VO2 max, not perceived effort; volume, reps times sets, so three sets of 10 is 30 and five sets of five is 25; rest intervals between sets; progression, whether by weight, reps, rest or complexity; and frequency, meaning how many times per week.

Galpin points out that progression doesn't need a heavier load. Moving from a single-joint machine leg extension to a whole-body squat is itself progressive overload. He suggests this is a good starting point for beginners, who should focus on correct movement patterns and on building "tissue tolerance" before thinking about intensity or rep ranges.