Here's the tension at the heart of this article, and it's one I've seen play out across dozens of studies in our knowledge base: the thing that feels like recovery might actually be working against you. Cold showers post-workout reduce soreness, which the body interprets as healing — but what's actually happening is that you're suppressing the very inflammatory signals your muscles need to rebuild stronger. A 12 percent reduction in muscle protein synthesis is not a small effect. That's measurable. That's real.
The testosterone claim is worth addressing directly, because it's the hook that draws most people into cold exposure in the first place. The science simply doesn't support it. If anything, several studies show a decrease in serum testosterone following cold water immersion. If your goal is to build muscle, chasing testosterone through cold showers is a path that leads nowhere useful.
Our knowledge base has a companion article — "Why Not Showering With Cold Water Is Killing Your Gains" — that reaches a nearly identical conclusion from a different angle, noting that cold water submersion has a more pronounced negative effect than showers alone. The mode of delivery matters. A cold plunge is more disruptive than a cold shower, which is more disruptive than a cold rinse. The dose shapes the outcome.
What I find genuinely important here is the data from the contrast therapy articles. Several sources I've reviewed draw a sharp distinction between cold exposure for performance adaptation versus cold exposure for acute recovery. They're not the same goal, and treating them as interchangeable is where most people go wrong. Elite athletes use ice baths because they need to compete again in 48 hours — they're trading adaptation for speed of recovery. That tradeoff makes sense in a competitive season. It makes less sense if you're training for long-term hypertrophy.
Everyone agrees on the mood and alertness benefits. Noradrenaline surges, beta endorphins release, your sympathetic nervous system wakes up. Cold showers in the morning, on rest days, or before a demanding cognitive task? Genuinely useful. The disagreement is specifically about the post-workout window — and there, the evidence is stacking up clearly against cold immersion for muscle builders.
Keep your cold shower. Just move it. Morning ritual on rest days — excellent. Immediately after lifting — step away from the cold tap and go for a slow cycle instead. Active recovery preserves the inflammatory signaling your muscles are relying on to adapt. Let them do their work first.
Here's what most people don't realize: the inflammation cold suppresses isn't your enemy. It's a message. When muscles are damaged by training, that inflammatory cascade is the body's repair crew arriving on site. Quench it too fast and the crew goes home. Hormesis requires the stressor and the recovery to run their full course. Cold exposure, like every other tool in this space, respects no shortcuts.