Boosting Testosterone & Understanding Your Testosterone Levels (Aging, Muscle Growth & Nutrition)

October 14, 2026

AI Summary

5 min read

The Real Story on Testosterone: Age, Obesity, and What Actually Moves the Needle

Dr. Andy Galpin opens this episode with a provocative claim that sets the tone for everything that follows: according to recent analyses by Dr. Ben House, total testosterone does not actually drop with age. The drop that everyone assumes is inevitable is instead driven almost entirely by obesity and metabolic dysfunction. When you tease those factors out, older men who maintain good metabolic health have as much testosterone as younger men—and sometimes more.

This is not a fringe position. Galpin walks through the data carefully, acknowledging that the widely cited statistic of a 1% annual decline after age 40 is not wrong, but it is misleading because it fails to account for body composition. In the analysis House has submitted for peer review, when you control for metabolic health, the age-related decline disappears entirely. In fact, the data show an increase of about 8 nanograms per deciliter per decade of aging in metabolically healthy men.

The Metabolic Health Framework

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What you'll learn

1 (00:06) **Episode Introduction & Why This Follow-Up Exists** - Dr. Galpin explains that this episode extends the previous conversation with Dr. Ben House, covering topics they didn't have time to explore fully.
2 (01:20) **The "No Drop in Testosterone with Age" Argument** - Galpin recaps Ben House’s novel finding that age itself doesn't cause a testosterone drop; metabolic dysfunction and obesity are the real drivers.
3 (04:24) **The Inverted U: Overfeeding vs. Undereating & Testosterone** - Galpin introduces the dual problem of low testosterone from both obesity (overfeeding) and from extreme caloric restriction (undereating) in lean athletes.
4 (10:01) **The Reality of the "Low T Epidemic"** - Galpin argues that while low testosterone is a real and fixable problem, it is not the epidemic often portrayed, especially for lean individuals.
5 (13:42) **The Other Side: Caloric Restriction & Testosterone in Lean Athletes** - Galpin pivots to undereating, explaining that 15-25% of elite athletes may have low testosterone due to caloric suppression.
6 (18:43) **The Inverted U: Body Fat, Caloric Deficit, and Testosterone** - Galpin details the curve: overweight individuals see testosterone rise with a deficit, while very lean individuals (below ~5% body fat) see it crash.
7 (29:52) **Age, Metabolic Health, and the Five Criteria** - Galpin dives into the data showing that metabolic health, not age, is the primary determinant of testosterone levels.

+ Full timestamped outline available in the app

Guests on this episode

Andy Galpin Gabrielle Lyon

Show Notes

In this episode, I explore testosterone and performance, building on my conversation with Dr. Ben House to take a closer look at how nutrition, metabolic health, and aging affect your hormones. I explain why excess body fat and underfueling can both suppress testosterone, how aggressive dieting differs from a modest calorie deficit, and what research suggests about hormone recovery after refeeding. I examine emerging findings on testosterone and aging, why metabolic health matters, and how total testosterone, free testosterone, and sex hormone-binding globulin (SHBG) can tell different stories. I also discuss the Defense Health Agency’s new testosterone guidelines for male service members, the importance of repeat testing, and what to consider before starting testosterone replacement therapy (TRT), including fertility and ongoing monitoring. We then look at testosterone’s role in muscle growth, why normal hormone levels and brief post-exercise increases do not reliably predict training results, and what androgen receptors can and cannot explain. I also discuss practical considerations for protein intake, anabolic resistance, and strength training as you age. This episode is for anyone who wants to better understand their hormone health and make more informed decisions about nutrition, training, and testosterone.

Sponsors

Momentous: https://livemomentous.com/galpin

David: https://davidprotein.com/perform

LMNT: https://drinklmnt.com/perform

Chapters

(00:00:00) Testosterone & Performance

(00:06:37) Low Testosterone: Lab Results, Symptoms & Obesity

(00:13:31) Underfueling, Calorie Deficits & Low Testosterone

(00:23:05) Testosterone Recovery: Refeeding, Sleep & Stress

(00:30:11) Testosterone & Aging: The Role of Metabolic Health

(00:44:39) New Testosterone Guidelines & Accurate Testing

(00:50:42) TRT: Safety, Fertility, Treatment Targets & Benefits