Essentials: How to Exercise for Strength Gains & Hormone Optimization | Dr. Duncan French

Welcome to Huberman Lab Essentials, where we revisit past episodes for the most potent, actionable tools for mental health, physical health, and performance. I am Andrew Huberman, a professor of neurobiology and ophthalmology at Stanford School of Medicine. Now, my conversation with Dr. Duncan French. Duncan, great to see you again.

Likewise. We do not get many Stanford professors at the Performance Institute, so I am excited.

I found dozens of your papers on how weight training impacts hormones. What about heavy loads and motor unit recruitment tells the endocrine system to release testosterone—and in women, is that adrenal only?

It is a mechanical plus metabolic stress response driving sympathetic arousal, catecholamines, and HPA axis signaling. In women, testosterone is adrenal. In men, both adrenals and testes contribute; the acute versus chronic impact is debated.

Testosterone is not just muscle, right? What about tendons, ligaments, bone, even neural tissue?

Androgen receptors are everywhere. I see adaptations in tendon, ligament, bone, and neural tissues, not just muscle. It is a powerful multi-system hormone.

Give me simple training principles to raise the anabolic environment for non-elites.

Intensity plus volume. Our go to: six by ten at eighty percent of one repetition max on big compound lifts, two minutes rest. Adjust load to hit ten reps. Ten by ten at eighty percent crushes intensity. Mechanical strain comes from load; metabolic strain from volume. Shorter rests heighten hypertrophy. Do that approximately two times per week and interleave higher-rep days and heavier, lower-volume days.

So high intensity, short duration, with honest two-minute rests to keep metabolic stress high—even if I have to lower the bar mid-session?

Correct. Rest is a primary variable. Two-minute rests drive more metabolic stress and growth than three-minute rests when the goal is muscle. Expect to suffer; limit that protocol to two times weekly unless you are bodybuilding.

You surprised me: acute stress can spike testosterone, like a parachute jump. Does mindset change that—choosing to jump versus being shoved?

Yes. Anticipatory arousal matters. Before brutal sessions we saw catecholamines rise up to fifty minutes prior. Athletes with bigger sympathetic responses sustained force longer. More arousal, better output—within individual limits.

Cold exposure for recovery—helpful or harmful?

It depends on intent. As a mindset stressor, fine. Physiologically, cold clamps vasculature and can blunt hypertrophy by dampening anabolic signaling. Periodize: avoid cold when chasing muscle; use it in competition phases to protect quality and speed recovery.

Are your fighters periodizing cold? And how do you view skill training volume versus quality?

We educate across sports on timing. The best pros build structure to repeat quality daily. Skill is quality-driven: rehearse precise mechanics and stop when fatigue degrades accuracy. Short, high-quality sessions beat long, sloppy ones.

Why does hard training feel mentally draining, and how should I fuel—low carb, keto, exogenous ketones?

Skill work is cognitively taxing—problem solving, dopamine, and brain energy needs. Glucose fuels the brain and high-intensity efforts; fully ketogenic diets rarely suit intermittent high-intensity athletes. We sometimes use exogenous ketones post-event for brain support. For the general population, cycling ketosis can improve metabolic efficiency. For fighters, we time carbohydrates pre, during, and post training, then run lower-carb meals the rest of the day.

Define metabolic efficiency and nutrition periodization. Did I get it: fats at low intensities, carbs at high, and switch diet with training blocks?

Exactly. Teach fat use at low intensities to spare glycogen so carbs are available when intensity spikes; the crossover point tells us a lot. Yes to periodizing diet with training. We also heat-acclimate: approximately two hundred degrees Fahrenheit sauna, building to thirty to forty five minutes; around fourteen sessions starting eight to ten weeks out increases sweat rate for weight cuts.

How long should I trial changes to heat, cold, diet, or training—twelve weeks?

About three months is enough to see meaningful change. Log training, sleep, mood, and performance. Responses are individual—think, adjust, and program for adaptation.

Duncan, I learned a ton. I am taking these protocols into my own training and nutrition. Thank you—let us do this again.

Thank you. This was a blast. Keep doing what you are doing—people love this platform.