Cold training: how ice baths and long exhales strengthen your stress system

In Finland, generations have been diving into icy lakes—not out of bravado, but rooted in a deep belief that cold makes you stronger. That mental resilience is what the Finns call Sisu: a mix of determination, inner calm, and mental strength. In winter, you’ll find entire swim clubs gathering to break the ice and plunge into freezing natural water. And they don’t do it for show. Today, science confirms what they’ve intuitively known for years: cold training has a profound impact on both body and mind.

Here in Western Europe, cold training gained popularity largely thanks to Wim Hof, also known as The Iceman. His extreme feats—like running barefoot marathons in snow or sitting in ice water for minutes—drew public attention to cold exposure. But you don’t need to go to extremes to enjoy the benefits. A gentle approach, combined with conscious breathing, is enough to gain real physical and mental advantages from cold training.

What is cold training and why is it so popular?

Cold training means deliberately exposing your body to cold—usually through cold water. This might include cold showers, ice baths, or swimming in cold natural water. The water temperature typically ranges from 5 to 15 degrees Celsius. Those first seconds are intense: your heart races, your breath catches, and your instinct tells you to get out. But when you're properly guided and in control of your breathing, something powerful happens—clarity, calm, and a deep sense of presence.

The health benefits of cold training

The health benefits of cold training are increasingly well supported by research. Studies show that it helps your nervous system switch more easily between stress and recovery modes. After an ice bath, heart rate variability (HRV) often increases—a sign of parasympathetic activation, meaning your body shifts into rest-and-repair mode. People report feeling less stressed and mentally clearer for up to 12 hours after a cold dip. Other studies highlight a hormonal effect or even describe a “hormonal storm”: dopamine, noradrenaline, and endorphins surge noticeably. It’s no coincidence that many people feel almost euphoric after a plunge.

The link between cold training and breathing

Cold training is not something to jump into impulsively. The moment you step into icy water, your body is hit by the cold shock response—a sudden gasp reflex, rapid heartbeat, and fast, shallow breathing. This reflex can be dangerous, especially if you're alone or unprepared. In one well-known study, participants who could hold their breath for 45 seconds saw that time drop to less than 10 seconds in 5°C water. Your nervous system simply panics.

This is where breathing makes all the difference. By consciously exhaling slowly and fully, you activate the vagus nerve, which helps regulate your stress response and brings you back into calm. You’re not just building mental resilience—you’re also training your body to stay regulated under pressure. In icy water, your exhale becomes your anchor.

Cold training in Finland: the power of Sisu

In Finland, people who regularly swim in cold lakes often report fewer winter blues or seasonal stress symptoms. That’s not only due to the cold itself, but also the routine and mindset behind it. They integrate it into their identity and way of life—Sisu is a daily practice, not a one-off challenge. And that’s exactly what cold training can bring you, too: greater clarity, resilience, and inner peace.

Cold training with Treebalance

As a breath coach, I always combine cold training with simple, grounding breathing techniques that keep your body safe and your mind steady. There’s no need to force or push yourself. In fact, the calmer you remain, the more powerful the effect. The combination of cold exposure and conscious breathing ensures your nervous system isn’t overwhelmed but gradually learns to process cold as a stimulus, not as a threat.

At TreeBalance, I guide people who want to explore cold training in a gentle, safe, and grounded way. We work individually or in small groups and build up step by step. You’ll learn how to stay calm through your breath, even when your body is surprised. No extreme challenges, just a clear and supportive approach that helps you feel, let go, and literally breathe through discomfort. And always with a warm cup of tea afterwards.

Want to experience cold training for yourself?

Are you curious what cold training could do for you? Do you feel your body is craving recovery, calm, or mental clarity? Then I warmly invite you to join a guided cold training session at Treebalance. 

💌 Have questions, want to join, or looking for upcoming sessions? Send me an email at annelies@treebalance.be or leave your details via the contactform..

Want to read more about breathwork and stress?

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👉 Discover the power of your breath – and how conscious breathing creates calm.