The first contact with ice water is not a wellness moment. It is a negotiation. The skin screams. The breath stumbles. The heart speeds up. And yet people get in again and again. Not out of courage. But because of what comes afterwards: calm. Clarity. Euphoria. A feeling as if someone had pressed the reset button.
When you dive in, your body releases noradrenaline, adrenaline and endorphins. The body's own mixture of alarm system and happy drug. Many winter bathers say afterwards: "Now I'm awake." You believe them immediately.
The moment when the body protests - and the brain applauds
Even in professional sport, sitting in the ice bath has become as much a part of the stage as the finish line. "Tour de France" stars such as Tadej Pogačar demonstratively step into cold water after hot mountain stages as if it were an extension of the shower - only more strategic. The idea behind it: To slow down inflammation, soothe muscles faster, prepare the body for the next day. Whether this actually helps build muscle in the long term is scientifically controversial. But one thing is certain: if you're travelling through France for three weeks, you'd rather sit in an ice buoy than on the couch. And sometimes in competitive sport, the feeling of having done something right is enough. This is because scientific studies rarely manage to depict the mental aspect.
Ice bathing: hip at the moment, but older than you think
Incidentally, the idea of voluntarily sitting in cold water is older than any ice buoy in the professional peloton. Even Johann Wolfgang von Goethe allegedly chopped up the ice of the Ilm to bathe in it - for health reasons, of course. In the 19th century, naturopaths such as Ernst Mahner publicly propagated winter bathing as a way of toughening up the body and character. And long before biohacking became a household word, "sea dogs", "icicles" and other cold-resistant organisations were already meeting in German rivers and lakes for communal shivering. So you could say: ice bathing is not a trend. It's a very old idea - only today with neon-coloured swimming caps.
The immune system goes to training camp
Cold forces the body to adapt.
Vessels contract. They then open up again. Blood circulation increases. The circulation works. Doctors call this vascular training. Winter bathers call it hardening.
Studies suggest that regular cold water stimulation can reduce stress, improve sleep and increase quality of life. One thing is certain: the blood vessels benefit. The psyche and metabolism probably benefit too. Much has not yet been definitively proven. But there are plenty of testimonials.
Brown fat, a good mood and the hope of fewer colds
The body has two types of fat. White fat stores energy. Brown fat burns it. Cold activates this brown fat. It produces heat instead of winter fat. An evolutionary relic from times without down jackets.
At the same time, winter bathers report fewer infections. Whether the immune system actually becomes stronger or is just in a better mood is still being researched. The good news: even cold showers can have similar effects. The bad news: showers make less of an impression when telling a story.
Studies on ice bathing show positive effects on blood circulation and the cardiovascular system. However, studies on long-term health effects are still scarce and many effects are based on experience reports rather than being substantiated by comprehensive long-term studies. Cold water swimming appears to have a positive effect on the immune system, with cold showers often showing similar effects. Some studies suggest that ice swimming may hinder muscle building after exercise if it is done too intensively or too quickly after exercise.
Cold shock is not a lifestyle product
Ice bathing looks like courage on Instagram. Medically, it's stress at first. Blood pressure and heart rate increase during immersion. The so-called cold shock can be dangerous - especially for people with cardiovascular diseases. That's why:
Never go into the water alone.
Never jump in. The drop in temperature can trigger a cardiac arrest.
Never stay too long.
Never start without a health check.
Rule of thumb: degrees = minutes. In other words: only stay in the water for as many minutes as the water has degrees Celsius. For beginners, much shorter is better.
Seconds in the water, stories for life
Winter swimming doesn't start in January. It starts in autumn. With cold showers. With courage. And with the first step into the water, which always remains the hardest.
Professionals even swim a so-called ice mile as a competition: 1.6 kilometres in water temperatures below five degrees. Without neoprene. Just swimming trunks, goggles and a swimming cap. Over 550 people worldwide have done this so far. Irishman Ger Kennedy holds the world record, he has attempted the ice mile 14 times in total, Paul Bieber from the Allgäu has done it 10 times so far; he is chasing the world record. You can do it. But you don't have to.
Records, headlines and people who stay longer than is reasonable
Dutchman Wim Hof spent almost two hours up to his neck in ice water.
Briton Lewis Pugh swam one kilometre in the Antarctic.
In December 2021, Krzysztof Gajewski from Poland swam almost four kilometres through 4.6-degree water - exactly 3.91 kilometres in Lake Kopalnia. A distance that would make normal swimmers curl their toes just thinking about it.
And Germany is also keeping up: Paul Bieber covered over 2.2 kilometres in Lake Constance in temperatures below five degrees. In swimming trunks. Without neoprene. But with a circulatory system that is obviously much more resilient than average.
And in March 2025, more than 2,400 people entered the cold water in the Czech Republic at the same time. A world record. You could say it was a trend. Or a collective nervous breakdown with a swimming cap. One thing is certain: Anyone who has ever bathed in winter suddenly understands why people voluntarily do things that they would previously have ruled out. For example, going back inside.
Health effects - what science (cautiously) suggests:
- Immune system & blood vessels: Regular ice baths appear to train the immune system and make the blood vessels more elastic and adaptable. Cold showers are said to have a similar effect.
- Hormone kick: The icy shock triggers a massive release of noradrenaline, adrenaline and endorphins - resulting in sudden feelings of happiness, increased alertness and razor-sharp focus.
- Regeneration in sport: Many athletes swear by it: exposure to cold can dampen inflammatory processes and noticeably speed up recovery after hard training sessions.
- Mental strength: Those who consciously face the cold shock not only train their body, but also their mind - the ability to endure discomfort and build mental resilience increases measurably. According to Christof Wandratsch, ice swimming requires you to overcome the cold in your head. Christof Wandratsch is one of the best-known ice water swimmers in Germany.
- Fat burning: There is promising evidence that cold stimuli activate brown adipose tissue. This "good" fat burns calories to generate heat - and could therefore boost the metabolism.
Dangers and risks
Well worth reading to get started with winter swimming and bathing: the basics of ice swimming of the German Swimming Association (Deutscher Schwimm-Verband e. V.) can be downloaded here.
Dimitri Lehner
Editor
