Transcript
A (0:00)
Welcome to Huberman Lab Essentials, where we revisit past episodes for the most potent and actionable science based tools for mental health, physical health and performance.
B (0:11)
I'm Andrew Huberman and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. And now my conversation with Dr. Duncan French.
A (0:20)
Duncan French, great to see you again.
C (0:22)
Likewise. Likewise. Thank you. I don't often have many Stanford professors in the performance institute, so I'm really excited.
A (0:29)
Oh, well, this place is amazing and you have a huge role in making it what it is. I found dozens of papers on how weight training impacts hormones, and your name's on all of them. What is it about? Engaging motor neurons under heavy loads sends a signal to the endocrine system. Hey, release testosterone. I've never actually been able to find that in a textbook.
C (0:54)
Yeah, I mean, I think it's a stress response, right? It's mechanical stress and it's metabolic stress. And these are, you know, the downstream regulation of testosterone release at the gonads comes from many different areas. You know, my work primarily looked at, you know, catecholamines and sympathetic arousal.
A (1:13)
So things like epinephrine, correct?
C (1:15)
Yeah, epinephrine, adrenaline, you know, noradrenaline, how they were signaling that signaling cascade using, you know, the HPA axis releasing cortisol. And then, you know, looking at how that also influenced the adrenal medulla to release, you know, androgens and then signaling.
A (1:34)
That, the gonads, that raises an interesting question. So in presumably weight training in women, people who don't have testes, also it increases testosterone. And is that purely through the adrenals? When women lift weights, their adrenal glands release testosterone.
C (1:49)
Absolutely. I mean, that is the only area of testosterone release for females. And yes, it's the same downstream cascade. Obviously, the extent to which it happens happens is significantly less in females. But that's how you. There's good data out there that shows, you know, females can increase their anabolic environment, their internal anabolic milieu, using resistance training as a stressor. And then they get the consequent muscle tissue growth, you know, whether it's tendon ligament adaptations, you know, the beneficial consequences of resistance training, which is driven by anabolic stimuli.
