Ice baths do not reliably increase testosterone. The available research shows that cold water immersion either has no immediate effect on testosterone or temporarily decreases it. One study found testosterone dropped by 10% during cold water exposure. There is some evidence that repeated exercise in cold environments may raise testosterone levels days later, but this appears to be a delayed adaptive response rather than a direct effect of cold exposure alone.
What Happens to Testosterone During Cold Exposure
The most direct evidence comes from a study measuring serum testosterone during cold water stimulation, which found levels decreased by 10%. At the same time, luteinizing hormone (the signal your brain sends to trigger testosterone production) increased by 22%. This pattern suggests the body may be attempting to compensate for the testosterone drop, but the net result during the exposure itself is still a decline.
This is the opposite of what many online claims suggest. The idea that cold exposure “shocks” the body into producing more testosterone sounds intuitive, but the acute hormonal data doesn’t support it.
The Delayed Effect After Repeated Cold Exercise
One finding adds nuance. A 2025 study published in Frontiers in Physiology had participants exercise in cold conditions daily for five days. Testosterone levels showed no change immediately after training. But when researchers checked again seven days after the protocol ended, total plasma testosterone had risen 56% above baseline.
This is a meaningful increase, but there are important caveats. The protocol combined exercise with cold exposure, so it’s difficult to separate the contribution of each. Cortisol also rose by 54%, which means the testosterone-to-cortisol ratio stayed essentially the same. That ratio matters because cortisol works against many of testosterone’s muscle-building effects. A proportional rise in both hormones doesn’t necessarily give you the benefits people associate with higher testosterone.
Ice Baths Don’t Change the Testosterone-to-Cortisol Ratio
The testosterone-to-cortisol ratio is often used as a marker of recovery status in athletes. A higher ratio suggests the body is in a more anabolic (tissue-building) state, while a lower ratio suggests more breakdown and stress. Research on cold water immersion after high-intensity exercise found no statistically significant differences in this ratio between athletes who used ice baths and those who didn’t. Under all conditions tested, including different durations of immersion, the ratio followed the same pattern: it dropped after exercise, stayed low for about an hour, then gradually returned to baseline within 24 to 48 hours.
In other words, ice baths didn’t shift the hormonal balance toward recovery any more than passive rest did.
Ice Baths May Actually Blunt Muscle Growth
If your interest in testosterone is really about building muscle, the research on ice baths and strength training is worth knowing. A study published in The Journal of Physiology compared people who used cold water immersion after strength workouts to those who did active recovery instead. The active recovery group gained significantly more strength and muscle mass.
Specifically, the active recovery group saw a 19% increase in work output, a 17% increase in the size of type II muscle fibers (the ones most responsible for strength and power), and a 26% increase in the number of muscle cell nuclei per fiber. The cold water immersion group did not see these gains. Cold water immersion reduced blood flow to the muscles during the recovery window, which likely lowered the rate of muscle protein synthesis. It also suppressed the activity of satellite cells, which are essential for muscle repair and growth, and reduced the activation of a key signaling pathway that drives hypertrophy.
These effects compounded over the course of the training program, leading to measurably smaller gains in both muscle size and strength. So even if ice baths did produce a small testosterone bump, the downstream effects on muscle tissue appear to work in the opposite direction.
Temperature and Duration in the Research
Studies on cold water immersion have used a wide range of protocols, and none have found a consistent testosterone boost. Water temperatures in the research range from near freezing (0 to 2°C, or 32 to 36°F) used in winter swimming studies, to moderately cold (10°C, or 50°F) for 15-minute sessions, to cool but not cold (14°C, or 57°F) for longer durations. A study looking at one-hour immersions at three different temperatures found that none of them increased cortisol, suggesting the hormonal stress response is more limited than people assume. Winter swimmers who trained three times a week for 12 weeks did show the body adapting to repeated cold exposure, but the adaptations documented were related to stress tolerance, not testosterone production.
Why the Claim Persists
The belief that ice baths raise testosterone likely stems from a few sources. Cold exposure does trigger norepinephrine release, which creates a feeling of alertness and energy that people may associate with higher testosterone. Some animal studies on testicular temperature and sperm production get extrapolated to human hormone levels, which is a stretch. And the general “hormesis” idea, that controlled stress makes the body stronger, is true in some contexts but doesn’t apply uniformly to every hormone.
The reality is simpler. Cold water immersion has documented benefits for mood, perceived recovery, and inflammation. Testosterone production is not one of them. If your goal is to optimize testosterone through lifestyle, the well-supported levers are consistent resistance training, adequate sleep (7 to 9 hours), maintaining a healthy body fat percentage, and ensuring sufficient intake of zinc and vitamin D. Ice baths can fit into a recovery routine for other reasons, but expecting them to move the needle on testosterone isn’t supported by the current evidence.