At its core, this is a beginner's argument for cold showers: they're uncomfortable, they build willpower, they wake you up, they boost circulation, and they may raise testosterone. That's the claim. And the person making it isn't citing a lab study — they're citing their own experience. They tried it, it was hard, they adapted, and they felt better. That personal testimony is worth something.
But "it feels good" and "here's why it works" are two different things. So let me add some depth.
The willpower argument is real, but the mechanism is more interesting than "suffering builds character." When cold water hits your skin, your sympathetic nervous system floods your body with norepinephrine — sometimes two to threefold over baseline. That neurochemical state is alertness, focus, drive. You're not learning to tolerate discomfort. You're training your nervous system to activate and then regulate under stress. That's a different thing, and it's a more useful thing to understand.
The circulation claim holds up too, but contrast is where the real cardiovascular benefit lives. Cold alone causes vasoconstriction — blood pulls toward the core. Warm alone causes vasodilation — blood spreads outward. Alternating between the two is what trains vascular flexibility. A cold-only shower is doing part of the work. Hot-cold contrast does more. The Finnish sauna research, which tracks nearly 1,700 people over years, shows dose-dependent effects on cardiovascular mortality — not from cold alone, but from the full thermal oscillation protocol.
The testosterone claim is where I'd pump the brakes. The logic — cold temperatures support testosterone production because the testes operate below core body temperature — is physiologically sound. But "cold shower raises testosterone" is a significant leap from that foundation. The studies that show meaningful hormonal effects use immersion, not showers. Duration and temperature matter enormously. A two-minute cold shower at the end of your warm shower is not the same stimulus as a 57-degree plunge pool.
That doesn't make the practice useless. It makes the claim imprecise. Honest framing matters here.
Start exactly as this video describes. Warm shower first. End cold. Thirty seconds. Bear with it. Increase over weeks. This is the right entry point. Don't reach for a cold plunge protocol before you've built the baseline tolerance that cold showers develop. The shower is the training ground.
Here's what most people miss about the "willpower" benefit: it's not metaphorical. The prefrontal cortex — your planning, self-regulation, decision-making center — becomes more active when you choose to stay in cold water despite your body's protest. You're literally practicing the act of overriding impulse with intention. That neural pattern generalizes. The person who can stand in cold water for two minutes without panicking is building the same circuitry they'll use when they need to resist a bad food choice, finish a hard conversation, or push through a difficult afternoon. The shower is a proxy for every moment that asks more of you than you want to give.