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

The episode opens with Andrew Huberman, who identifies himself as a professor of neurobiology and ophthalmology at Stanford School of Medicine, introducing Dr. Duncan French. French is described as Vice President of Performance at the UFC Performance Institute, with over 20 years of experience working with elite, professional and Olympic athletes, and as the former Director of Performance Sciences at the University of Notre Dame. His peer-reviewed work is presented as exploring how exercise order, such as endurance exercise before or after resistance training, affects performance and hormones including testosterone, estrogen and cortisol.

The introduction also points to work on how neurotransmitters such as dopamine and epinephrine (adrenaline) interact with hormones in both directions, and to training protocols designed to maximize testosterone output or reduce stress hormone output to improve training effects in the short and long term. The stated aim is practical: protocols on training duration and type that recreational exercisers, amateur and professional athletes, and health-focused people can apply. The host notes that the podcast is separate from his Stanford teaching and research roles.

Early in the discussion, a contrast is drawn between formal exercise physiology, with designed studies and control groups, and the internet and social media version of exercise science, where people put forward ideas about training and eating. The point is qualified with the acknowledgement that science does not have all the answers.

The career account given in the conversation stresses authenticity alongside academic rigor, objectivity and a knowledge base, and the ability to speak with coaches, athletes, CEOs and academics on successive days. The speaker counts work across 36 different professional or Olympic sports, "last time I counted." The most unusual is crown green bowling, described as a 20 foot by 20 foot square of turf with a raised crown in the middle, where players roll larger balls to get closest to a smaller white jack.

The background described starts in Harrogate, Yorkshire, in the northeast of England, with undergraduate study in sports science, teacher training and work as a high school physical education teacher. The speaker calls themselves "a failed athlete, like many people," having represented their country in different sports without making it professionally. That ambition to reach the higher end of elite sport led to applications for a PhD in the U.K. and the United States, framed as a way to continue studying while gaining life experience abroad.

After many rejections and persistent cold contact, Dr. William Kramer, then at Ball State University in Indiana and described as a muscle neuroendocrinologist, offered guaranteed funding for the first year but not the following three. With family support, the PhD began at Ball State; after a year Kramer moved to UConn in Storrs, and the student moved too. The group is described as prolific, studying neuroendocrinology and hormonal responses using resistance training as the primary exercise stressor. The PhD field is given as exercise physiology.

The discussion raises a question said to be missing from textbooks: what about loading motor neurons under heavy weights tells the endocrine system to release testosterone? The answer offered, explicitly from memory, is the stress response, meaning mechanical and metabolic stress, with testosterone release at the gonads regulated downstream from many different areas. The research focus described was catecholamines and sympathetic arousal.

The proposed cascade involves epinephrine, adrenaline and noradrenaline signaling through the HPA axis to release cortisol, influencing the adrenal medulla to release androgens, and signaling the gonads. When asked about people without testes, the response is that resistance training also raises testosterone in women, that the adrenals are "the only area of testosterone release for females," and that the extent is significantly less. The speaker cites "good data" showing that women can increase their internal anabolic milieu through resistance training, supporting muscle growth and tendon and ligament adaptations.

For men, the answer is openly unsettled: "The field is divided presently." One view emphasizes the acute, stress-driven response to exercise, which may come partly from the adrenal glands and partly from the gonads. The other emphasizes long-term exposure to an anabolic environment, mainly driven by the gonads, through elevated basal testosterone. The split concerns whether acute responses are significant enough to drive hypertrophy compared with habitual levels. The conversation summarizes this as probably both.

Testosterone's effects are described as reaching beyond muscle. Androgen receptors are said to be present on neural tissue and axons, and testosterone is described as influencing ligaments, tendons and, "to some extent," bone, including potential to counter osteopenic characteristics. The speaker calls it "a magic hormone, let's say," with many end impacts on adaptation.