Cold Plunge and Testosterone: What the Data Shows

Key insights

  • No controlled human trial shows cold water immersion raising testosterone; the closest direct test - ten-minute showers at 17 degrees C on four consecutive days in eleven male athletes - found no significant group-level change in salivary testosterone 1.
  • Applied straight after lifting, cold does the opposite of what the claim promises: 15 minutes at 15 degrees C after back squats left testosterone essentially flat (-0.5%) while passive recovery rose 9.2%, with values suppressed below pre-exercise at 30 and 60 minutes 2.
  • Severe cold lowers testosterone acutely: two to three minutes in water below 4 degrees C at -15 degrees C air dropped core temperature from 36.45 to 31.55 degrees C and produced a significant fall in circulating testosterone within seven minutes of exit (p = 0.000037), though values stayed inside the normal reference range 3.
  • Contrast bathing is hormonally neutral for testosterone rather than anabolic: a repeated sauna-plus-cold-immersion protocol in young physically active men moved testosterone from 4.04 to 4.25 ng/ml, a non-significant change, while cortisol fell 4.
  • The practical concern is not your T level but blunted adaptation: twelve weeks of post-workout cold water immersion attenuated gains in muscle mass and strength compared with active recovery, which makes timing the variable worth managing 5.

Ask a room full of people why they plunge and testosterone comes up within about thirty seconds. The claim circulates in a specific form: cold exposure raises testosterone, therefore a daily ice bath is an endocrine intervention. It is one of the few claims in this field where the underlying literature points clearly in the opposite direction from the marketing.

There is no controlled human trial showing that cold water immersion raises testosterone. The measurements that exist show it unchanged under most resting conditions, and reduced - sometimes sharply - when the cold is severe or when it follows hard resistance training. The direction of the acute effect is down, not up.

That is not an argument against cold plunging. It is an argument against plunging for that particular reason, and for a small change in when you schedule it. What follows is where the claim came from, what the measurements actually show, and the one protocol adjustment that matters.

Where the claim comes from

Two threads feed it. The first is a category error about the testes. Heat genuinely impairs spermatogenesis - the scrotum sits outside the body for a reason - so it is intuitive to assume that cooling the region must therefore raise androgen output. But sperm production and Leydig-cell testosterone synthesis are different processes under different control. Spermatogenesis is temperature-sensitive; testosterone secretion is driven by pituitary luteinising hormone, and several minutes of ice-water swimming has not been shown to move LH.

The second thread is looser: cold raises catecholamines, catecholamines feel anabolic, therefore cold is anabolic. Noradrenaline does rise steeply in cold water, and that is a real and interesting effect. It is simply not an androgen effect, and the papers that measured both found the two dissociate.

What a plunge does to testosterone in the moment

The most extreme measurement available comes from a 2025 study of thirteen young healthy men immersed for two to three minutes in a tub of water below 4 degrees C, positioned inside a refrigerated truck held at -15 degrees C air temperature. Total cold exposure was roughly five minutes. Core temperature fell from 36.45 to 31.55 degrees C - moderate hypothermia - and fasting blood was drawn within seven minutes of exit 3.

Testosterone fell, and the authors describe the reduction as very strong (p = 0.000037). Every post-immersion value nonetheless remained inside the laboratory reference range, alongside improved renal markers and modest rises in liver and cardiac enzymes that also stayed within normal limits. The authors' own conclusion is that a short immersion of this kind does not constitute a health hazard in healthy young men. The honest reading is that a hard plunge is a genuine acute stressor with a measurable transient hormonal signature, not that it damages the gonadal axis.

Two caveats keep this in proportion. Blood drawn seven minutes after moderate hypothermia captures the peak of a stress response, not a steady state; nobody has followed those men to see how quickly the value recovers. And water below 4 degrees C in -15 degrees C air is far colder than a domestic plunge, most of which run between 10 and 15 degrees C.

The closest thing to a direct test

If the popular claim is that a daily cold habit raises baseline testosterone, the study that tests it most directly is a 2026 research communication in Health Science Reports. Eleven current or former male college athletes took ten-minute cold showers at 17 degrees C on four consecutive days, with salivary testosterone measured across the protocol 1.

Nothing happened. Individual responses scattered in both directions - some men rose, some fell, several barely moved - and the group-level analysis showed no statistically significant change. The authors are appropriately modest about it: eleven participants over four days is a small, short study, and showers are a milder stimulus than immersion. But it is a fair test of the claim as it is usually made, and it came back null.

Cold after lifting: where the effect is real, and unhelpful

The one setting where cold water reliably moves testosterone is immediately after resistance training - and it moves it down. Eleven resistance-trained men performed six sets of ten back squats at 80% of maximum, then completed either 15 minutes of immersion at 15 degrees C or passive recovery, crossing over a week later. Blood was sampled before exercise and at 5, 15, 30 and 60 minutes afterwards 2.

Passive recovery produced the familiar post-exercise rise, up 9.2% relative to baseline. Cold water immersion produced essentially nothing, a change of -0.5%, with concentrations sitting below pre-exercise values at 30 and 60 minutes. The same protocol blunted the interleukin-6 and TNF-alpha responses. Cold does not suppress testosterone in general; it suppresses the exercise-induced rise, which is a narrower and more useful statement.

Whether that acute blunting translates into worse training outcomes is a separate question, and the answer appears to be yes at the margin. A twelve-week trial comparing post-session cold water immersion against active recovery found attenuated acute anabolic signalling and smaller long-term gains in muscle mass and strength in the cold condition 5. We looked at that literature in more detail in our piece on cold plunging after a workout.

What about contrast bathing?

Pairing heat with cold does not rescue the hormone story. A study of repeated Finnish sauna exposure combined with cold water immersion in young physically active men measured testosterone, cortisol, prolactin and DHEA-S before and after the protocol. Testosterone moved from 4.04 to 4.25 ng/ml - a non-significant difference within normal biological variation - while cortisol fell significantly 4.

That pattern is worth sitting with, because it is the same one that emerges from the heat literature on its own. Contrast bathing is a credible tool for downregulating a stress response. It is not an androgen intervention, and no reading of the data supports selling it as one.

Realistic expectations

Taken together: there is no controlled evidence that cold plunging raises testosterone acutely, and none that it raises it chronically. The acute measurements that reach significance point downwards, they occur under severe cold or immediately after heavy lifting, and in healthy young men the values remain within the reference range. Nothing in this literature suggests that a sensible plunge habit damages endocrine health.

Two limitations deserve stating. Almost every study here is small, male, young and athletic, with sample sizes in the low double digits; none of it speaks to older men, to women, or to anyone with an existing endocrine condition. And salivary and serum testosterone both fluctuate substantially by time of day, sleep quality and recent training, which is precisely why single post-exposure draws should be read as snapshots rather than verdicts.

If you suspect a genuine androgen problem, the answer is a morning blood panel and a physician, not a colder tub.

Practical protocol

Do not plunge for testosterone. Plunge for the things cold actually delivers - alertness, mood, perceived recovery from fatigue - and let the hormone question go.

If hypertrophy or strength is the goal, separate cold from lifting. Four to six hours of gap is the usual recommendation, and plunging on non-training days, or before rather than after a session, sidesteps the problem entirely. If you are deep in a competition block where recovering by tomorrow matters more than adapting by next month, the blunting is a reasonable trade and you should make it deliberately.

Keep the dose within the range the recovery literature actually used: roughly 10 to 15 degrees C for 10 to 15 minutes. Colder is not a bonus. The sub-4 degrees C exposures produce a substantially larger biochemical stress signature without a matching increase in benefit, and they carry a cold-shock risk that a 12-degree tub does not. If you want a number to track, use morning serum total and free testosterone across a normal week rather than a reading taken minutes after a plunge.

The Contrast Market Perspective

Everything useful in this literature is a statement about dose and timing - how cold, how long, how far from your last set. That only transfers to your setup if the tub holds the temperature it claims through repeated daily use, rather than drifting three or four degrees between sessions and quietly changing the stimulus you think you are applying. Sizing a chiller correctly to water volume, insulation and ambient conditions is unglamorous work, and it is most of what determines whether your protocol is repeatable. If you would like help specifying a plunge you can actually hold to a number, Schedule a consultation.

References

Footnotes

  1. Traylor et al. (2026). A four-day cold shower protocol does not increase salivary testosterone in a small cohort of male athletes: a research communication. Health Science Reports. PubMed Central ↩︎
  2. Earp, J. E., Hatfield, D. L., Sherman, A., Lee, E. C., & Kraemer, W. J. (2019). Cold-water immersion blunts and delays increases in circulating testosterone and cytokines post-resistance exercise. European Journal of Applied Physiology, 119(8), 1901-1907. PubMed ↩︎
  3. Teległów, A., & Cicha, I. (2025). Single immersion in cold water below 4 degrees C: a health hazard in young healthy men? PLOS ONE, 20(5), e0324502. PubMed ↩︎
  4. Podstawski, R., Borysławski, K., Pomianowski, A., Krystkiewicz, W., & Żurek, P. (2021). Endocrine effects of repeated hot thermal stress and cold water immersion in young adult men. American Journal of Men's Health, 15(2). PubMed ↩︎
  5. Roberts, L. A., Raastad, T., Markworth, J. F., et al. (2015). Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. The Journal of Physiology, 593(18), 4285-4301. PubMed ↩︎