Sean Smiley's story is remarkable, and I want to be careful about how we hold it. A firefighter sustains a serious testicular injury, testosterone drops into the sub-200s, and after a few weeks of jumping into a cold saltwater pool, his levels climb to 771. That's not a marginal improvement. That's nearly a fourfold recovery. And the weight loss — 30 pounds without apparently changing much else — suggests something systemic shifted, not just one biomarker.
The core claim is this: deliberate cold exposure, particularly before or after physical training, can meaningfully support testosterone production. Not as a supplement. Not as a drug. As a signal your body already knows how to respond to.
Here's where I need to be honest with you. The formal science on cold water immersion and testosterone is genuinely mixed. There's a frequently cited 1993 study that's nearly impossible to verify. The cold showers research in our knowledge base is blunt about it: direct scientific evidence linking cold immersion to testosterone increase is thin. Anecdote and speculation dominate the conversation.
But — and this matters — the adjacent research is much stronger. Dr. Tom Seager's work on ice baths and testosterone best practices, which we've indexed extensively, finds that cold exposure before exercise is the key variable. Not after. The sequencing changes everything. And Dr. Thomas's research reinforces this: reversing the conventional order, cold first then training, appears to prime the nervous system and hormonal response in ways that post-workout cold does not.
The disagreement isn't really about whether cold exposure affects hormones — norepinephrine spikes are well-documented, mitochondrial adaptations are real, and metabolic effects are measurable. The disagreement is about mechanism and reproducibility. Does cold directly stimulate Leydig cells to produce more testosterone? Or is the effect indirect — better sleep, reduced cortisol, improved metabolic health, lower inflammation — all of which create conditions where testosterone naturally rises? Sean's weight loss of 30 pounds may actually be the story here. Adipose tissue converts testosterone to estrogen. Less body fat alone could account for a substantial portion of his hormonal recovery.
If you're exploring cold exposure for hormonal health, the sequencing research is your most actionable guide. Try cold immersion before your training session rather than after. Even 5–10 minutes in cold water before you lift or move seems to prime the hormonal environment differently than the post-workout plunge that's become the default protocol. Start short. Build gradually. Consistency over duration.
Here's what most people miss when they hear Sean's story. The testes aren't located inside the body by accident. They sit outside the core precisely because sperm production and testosterone synthesis require temperatures roughly 2–4 degrees cooler than core body temperature. The scrotum exists as a thermoregulatory organ. When Sean's harness injury compressed that tissue and disrupted normal blood flow and temperature regulation, he may have been dealing with something simpler than full hypogonadism: localized thermal dysfunction. Cold immersion — especially in a full saltwater pool — may have helped restore the thermal environment those tissues were biologically designed to inhabit. Not a cure. A correction. That's a very different story than "cold baths magically raise testosterone," and it's a more interesting one.