Sixty seconds in ice water in the morning. That is the ritual Barcelona footballer Ferran Torres describes as his way of starting the day - and one neuroscience now has more to say about than the fitness industry would like.

„I put my whole body in cold water for a minute because it is a way to handle stress better. On top of that, it helps you activate and get energy”, he explained on the Miobio podcast. After training he submerges his legs for eight to ten minutes, and in the afternoon, after a sauna, he finishes with another minute of cold water. While he is in there, he works on his breathing and on visualisation - meaning the mind has a task while the body is under stress.

Neuroscientist Nicola Vignola describes cold water as „one of the easiest ways to expose yourself to something very, very hard”. The mechanism is direct: when skin receptors register a sharp drop in temperature, the signal reaches the brain, the sympathetic nervous system activates and the release of noradrenaline increases - a substance tied to attention and arousal.

Her main argument is more interesting than the cold water itself: „If we look at dopaminergic activity, the basic rule is that there has to be effort for there to be reward.” In other words, the satisfaction you feel once you get out does not come from the water but from having done something unpleasant on purpose. That is a mechanism that works outside the tub as well.

What the numbers show

A systematic review and meta-analysis published in PLOS One covered eleven studies with 3,177 healthy adults immersed in water of 15 degrees or below, for durations from thirty seconds to two hours. The finding: a significant reduction in stress twelve hours after exposure. Not immediately. And not after 24 or 48 hours. Some studies also recorded improved sleep quality, but the authors themselves warn that the evidence is still limited.

Vignola also talks about the so-called cold shock proteins, particularly RBM3, being researched for a possible role in preserving and restoring neural connections. The results are promising - in animals. In humans the evidence is thin, and she does not hide that.

Where the story stops

Plunging suddenly into very cold water can trigger a cold shock response - an involuntary gasp and rapid breathing leading to hyperventilation. Cold also brings changes in blood flow, so people with heart problems should ask a doctor first. The recommendation is gradual acclimatisation, with short exposures and less extreme temperatures. And one non-negotiable rule: in open water, never alone.

What is worth remembering from all of this is not that cold water is a miracle. It is that the reward comes from the effort - and that lesson needs neither a tub nor ice.