Ice Bathing - What Science Says, Myths, and How to Start Safely

Nikolai Gerstner
2 days ago
13 min read

- By Nikolai Gerstner, Co-Founder of Mindful Warriors, Sport Scientist and Boxing Coach

Structure of the Blog Post:

1) What Happens in the Body During Cold Exposure

2) Science-Backed Benefits

3) Risks and Common Myths

4) How to Start — From Cold Showers to Ice Baths

5) Why I personally keep doing It

6) What to remember from the Blog Post

In recent years, cold exposure - also known as ice bathing - has gone from niche practice to global trend. Athletes, entrepreneurs, and everyday people are diving into cold water in search of better focus, recovery, and resilience.

But what’s really behind it? What happens inside our body when we expose ourselves to cold? And what does science actually say about it?

*Photo: Ice bathing during one of the retreats near Tegernsee in 2025*

For me, the fascination with the cold began quite some time ago.

As a teenager, I walked from time to time outside in winter wearing only a T-shirt - the cold made me feel sharp and alive.

In 2017, during my amateur boxing years, I discovered the Wim Hof Method - and that’s when I began to understand the mechanisms and power behind cold exposure.

Through Wim Hofs 10-Week Video Course, I learned how to combine breathing, gradual exposure, and mindset, and since then I’ve explored ice bathing both through personal practice and sport science research.

In this post, I want to share what I’ve learned - how it works, what science confirms, what’s misunderstood, and how to begin safely.

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1. What Happens in the Body During Cold Exposure

1.1 Cold Exposure in General

First, the blood vessels near your skin narrow to hold on to heat (vasoconstriction). This reaction keeps your core warm and protects your vital organs by reducing blood flow to the surface, where heat would otherwise escape.

Your blood pressure rises temporarily, because the same amount of blood now flows through narrower vessels.This is completely normal - it’s your body’s first line of defense against losing warmth.

At the same time, your heart rate and breathing increase as part of the body’s built-in action mode - the sympathetic nervous system. It releases adrenaline and noradrenaline, hormones that make you alert, focused, and ready to react.

If you stay in the cold longer, your body starts to adapt. In some cases, muscles begin to shiver to generate heat, but this doesn’t always happen - especially in people who are more experienced or relaxed in the cold.

Your brown fat tissue also becomes active, burning energy to create warmth from within - a kind of natural heating system that gets stronger with regular practice.

Once you come out of the water and start to warm up, your blood vessels widen again, helping blood and oxygen flow freely through the body.

BUT: Interestingly, when you learn to relax inside the cold, something special can happen:

Your blood vessels may widen even while you’re still in the water, creating a wave of inner warmth that many people describe as a “heat from within.”

With consistent practice, your nervous system learns to handle stress differently - not only in the ice bath but in everyday life. You train your body and mind to recognize a stressful situation, stay calm, and recover faster.

That’s why cold exposure can be called a hormetic stressor - a short, controlled challenge that makes you more resilient over time.

1.2 Cold Showers vs Ice Bathing

Both cold showers and ice baths trigger similar reactions in the body, but the intensity and depth of those reactions are very different.

Cold showers mostly affect the skin and surface circulation. They give your body a mild version of the cold response - heart rate and breathing rise, blood vessels tighten, and hormones like adrenaline and noradrenaline are released. It’s an easy and safe way to build consistency and resilience, especially when practiced daily.

Ice bathing - The cold reaches the muscles and core, and the body reacts by raising blood pressure and directing warm blood toward the vital organs to protect them. At first, the shock can feel intense - you might instinctively want to get out right away. But when you breathe calmly and relax, your body finds balance. The heart rate stabilizes, the stress hormones settle, and you can reach a focused, calm state even in the cold.

This is where the biggest difference lies: Cold showers build daily discipline and stress tolerance - a steady, manageable habit. Whereas Ice bathing trains exposure to extreme stress - a skill that strengthens both the body and the mind.

Ice bathing in a mountain waterfall near Munich — *Photo: Ice bathing during a hike next to Munich.*

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2. Science-Backed Benefits

Over the last two decades, cold exposure has been studied by scientists worldwide - from exercise physiology labs to neuroscience institutes. While the hype often oversells it, research does show clear, measurable benefits when practiced consistently and safely.

1) Metabolism and Fat Activation

Cold exposure increases metabolic rate because the body needs to generate heat to maintain its core temperature. One interesting mechanisms is the activation of brown adipose tissue (BAT) - a type of fat that burns energy to create heat.

Early work by van der Lans et al. (2013) showed that repeated cold exposure at around 15–16 °C increases brown-fat activity and improves temperature regulation. However, this was done through air exposure (not ice baths), so while it shows potential for cold adaptation, the direct effects of cold-water immersion on brown-fat activation still need stronger evidence.

2) Reduced Inflammation

Cold exposure helps recovery - but not always for the reasons people think.

A 2022 meta-analysis (Moore et al.) found that cold-water immersion can speed up recovery of muscle power, reduce soreness, and lower muscle damage markers (Creatine Kinase - CK) within 24 hours after hard training.Shorter sessions (under 15 minutes) and colder water (below 10 °C) worked best for these short-term recovery effects.

However, Peake et al. (2017) showed that cold-water immersion after strength training was no more effective than active recovery for reducing inflammation or cellular stress inside the muscles. In short: Cold helps you feel and perform better faster - but it doesn’t necessarily make your muscles recover or grow faster. Use it on rest days or 6-8 hours after training, not right after lifting, if your goal is muscle adaptation.

3) Immune System Support

In a controlled experiment, Kox et al. (2014, PNAS) showed that participants who combined cold exposure with specific breathing techniques (as popularized by the Wim Hof Method) produced stronger immune responses and less inflammation after exposure to a bacterial toxin.

While this doesn’t mean ice baths “boost immunity” instantly, regular exposure may help the immune system become more adaptive and balanced over time. A large randomized study (Buijze et al., 2016) also reported a 29 % reduction in self-reported sickness absence after 30 days of daily cold showers, suggesting a possible behavioral or resilience-based benefit.

4) Physical Recovery

Cold-water immersion supports recovery after intense exercise. The strongest effects are seen with 10-15 minutes between 5-15 °C (dose depends on outcome), while shorter bouts can still aid perceived recovery and power according to earlier reviews.

10–15 minutes at 5–10 °C → best for improving CK and neuromuscular recovery.
10–15 minutes at 11–15 °C → best for reducing delayed-onset muscle soreness (DOMS).

Timing still matters: if you jump into cold water immediately after strength or endurance training, you may limit adaptation. It’s better to wait 6-8 hours before immersion if your goal is hypertrophy. If the goal is rapid recovery - for instance, between competitions - immediate use can be beneficial (Huberman Lab, 2022; Wang et al., 2025).

5) Mental Clarity and Hormonal Effects

Cold exposure strongly activates the sympathetic nervous system, releasing adrenaline (epinephrine) and noradrenaline (norepinephrine). These chemicals increase alertness, sharpen focus, and heighten energy levels for several hours afterward.

Morning cold showers or short ice immersions are particularly effective for setting the nervous system into a clear, focused state for the day (Huberman Lab, 2022; Briganti et al., 2023 Systematic Review).

6) Building Resilience and Stress Tolerance

When you step into cold water, your first instinct is to get out — that’s the body’s “fight-or-flight” response. But when you stay calm, focus on your breath, and relax into the cold, you train your brain to regulate that stress.

This engages the prefrontal cortex, the part of the brain responsible for control, planning, and decision-making. Over time, this strengthens mental resilience — the ability to stay composed and clear-minded under pressure (Huberman Lab, 2023; Briganti et al., 2023).

7) Mood and Motivation

Cold exposure can significantly affect mood through the prolonged release of dopamine, the neurotransmitter associated with motivation, focus, and well-being.

Studies show that even short exposures (1–3 minutes) can keep dopamine levels elevated for hours afterward, improving both mood and mental clarity. Many people describe the feeling afterward as calm but energized - a balance between focus and relaxation(Huberman Lab, 2022; Huttunen et al., 2004).

8) Sleep and Circadian Rhythm

When done early in the day, cold exposure acts as a strong wake-up signal for the body. This helps reinforce your circadian rhythm - making you more alert in the morning and promoting better sleep quality at night.

Some studies also link regular cold exposure to improved sleep satisfaction and a modest increase in overall quality-of-life scores.(Huberman, 2022)

In short: Cold exposure helps your body recover faster, sharpen your mind, and build resilience, but it’s not a magic shortcut. It’s a short, controlled form of stress. When practiced regularly, safely, and with intention, it trains both body and mind to handle challenges more effectively - in the ice, and in everyday life.

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3. Risks and Common Myths

While cold exposure can be a powerful tool, it’s not without risk.

Key Risks:

Cardiovascular strain - When you enter cold water, blood vessels tighten and blood pressure rises. For most healthy people, this is harmless and temporary - but for anyone with heart or circulation issues, it can be risky. Always check with a doctor before starting if you have cardiovascular conditions or high blood pressure.
Afterdrop - Even after you get out of the water, your core temperature can continue to drop for several minutes. This is called afterdrop and happens because cold blood from your skin flows back toward your core. That’s why it’s important to warm up gradually after the ice bath - with movement, warm clothes, or tea, not by jumping straight into a hot shower.
Temporary immune fatigue - Immediately after intense cold exposure, the immune system experiences short-term fatigue before it rebounds stronger.If you’re already sick or exhausted, it’s best to wait until you feel better before doing an ice bath.
Overexposure - Spending too long in the cold can lead to numbness, disorientation, or even hypothermia.Beginners should always start small — 30 seconds to 2 minutes is often enough. Consistency and good recovery matter far more than duration.

Common myths:

“The longer, the better.”- Not true.
Most physical and mental benefits plateau after 2–5 minutes. Staying longer mostly increases risk, not reward.

“Ice bathing is the best recovery method after strength training.” - Only partly true. If your goal is to build muscle, cold exposure immediately after training can reduce muscle growth. By reducing inflammation, it also reduces the body’s adaptation signals for hypertrophy (Roberts et al., 2015; Yamane et al., 2015). However, for athletes focused on skill, technique, or rapid recovery between sessions, it can be useful.

“Cold boosts immunity instantly.” - Not true. Adaptations take time. A single cold shower won’t “boost” your immune system — but consistent exposure over weeks helps the body adapt to stress and regulate inflammation better.

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4. How to Start - From Cold Showers to Ice Baths

Like any form of training, cold exposure works best when you build it step by step. Start simple, stay consistent, and give your body time to adapt.

Cold Showers

Cold showers are the easiest entry point. They give you a mild version of the same physiological reaction - higher alertness, tighter blood vessels, and controlled breathing practice - without strong cardiovascular stress.

How to begin:

Start with warm water and finish cold.
Move gradually when exposing the body to cold water: right leg → left leg → right arm → left arm → chest → back (This helps your body adjust instead of shocking it all at once).
Focus on slow, steady breathing - through the nose if possible.
Begin with 20-30 seconds of cold, then build up to 1-2 minutes over time.
Try to do it daily, especially in the morning for an energizing start.

Cold showers are perfect for building discipline and stress control - learning to stay calm when your instinct says “get out.”

Ice Bathing

Once you’re comfortable with the cold, ice bathing takes the practice deeper.

Full-body immersion challenges both body and mind more intensely and strengthens your ability to stay composed under real stress.

How to begin:

Enter slowly, submerge up to your shoulders.
Try to stay relaxed - tensing increases stress hormones - focuse on nostril breathing.
Start with 30 seconds – 1 minute; progress gradually.
Exit before shivering becomes intense.
Warm up naturally afterward (movement, tea, breathwork - not instant hot shower).
Practice in a group or guided setting for safety and support.

A quick anecdote: Once, a participant “didn’t feel the cold” and stayed 7+ minutes on their first try - but couldn’t rewarm properly for hours. Cold demands respect. Start small; consistency beats intensity.

Mindset

The goal isn’t to fight the cold. It’s to meet it with awareness - breathe, relax, and notice that you can find calm inside discomfort. That’s the same skill that translates to daily life: facing pressure without losing control.

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5. Why I keep doing It

For me, cold exposure has become more than a physical practice - it’s a mental reset. Every time I step into the water, there’s that familiar moment of resistance - the mind saying “not today.”

And that’s exactly where the training begins.

Once I slow my breathing and stop fighting the cold, it shifts.

The body softens, the thoughts quiet down, and there is a clear metnal focus.

It’s not about proving toughness - it’s about learning to stay calm when everything in you wants to escape.

That skill transfers into daily life. When stress hits - in training, work, or decision-making - I can feel the same rhythm: breathe, relax, act with control.

It’s a simple but powerful feedback loop between body and mind.

From a physiological side, the repeated cold exposure also helps my nervous system adapt faster. I feel that my stress response turns on and off more efficiently.

Whether you do it for recovery, mental clarity, or self-discipline, the key isn’t to fight the cold - it’s to meet it. Breathe into it. Relax through it.

And let it remind you how capable your body and mind already are.

The goal is not to fight the cold, but to accept it, breathe through it and learn to relax in a stressful situation.

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What to Remember

1. Safety first.

If you have heart or circulation problems, talk to your doctor before starting.

Begin with alternating showers, then cold showers, build up slowly, and avoid doing full-body ice bathing alone especially as a beginner.

2. How the body reacts:

Blood vessels tighten to keep the core warm.
Heart rate and blood pressure rise briefly.
Hormones like adrenaline and noradrenaline boost alertness and focus.
With practice, you learn to relax inside the stress - teaching your body and mind to handle stress with more control.

Duration - how long should you stay in?
Most benefits happen within the first few minutes. Studies show that 10-15 minutes total per session at 5-15 °C is effective for recovery and inflammation reduction (Wang et al., 2025). If your goal is focus, alertness, or stress resilience, shorter times of < 5min can be enough. Longer times mostly increase discomfort and risk rather than benefit - consistency matters more than duration.
Temperature - how cold is “cold enough”?There’s no single “right” temperature. Everyone reacts differently.A good guideline is:
"Cold enough that you want to get out, but you can safely stay in" - Huberman,2022. For most people, this means 10-15 °C for ice baths, or around 15-20 °C for cold showers. The colder the water, the shorter the exposure needed.
Cold Showers vs Ice Baths - which one is better?
Cold showers and ice baths trigger similar responses, but at different intensities. Cold showers mainly affect the skin and are easier to do daily - making them ideal for building a consistent routine. Ice baths cause a stronger full-body response (more hormonal activation and vascular adaptation) and are therefore better for deeper physical and mental training. The takeaway: Consistency is key. Ideally you combine regular cold showers and occasional extreme ice baths.
Benefits of Cold Water Immersion
1. Activates brown fat, boosting metabolism and thermoregulation (van der Lans et al., 2013).
2. Reduces inflammation and aids recovery (Peake et al., 2017).
3. Strengthens immune response and lowers chronic stress (Kox et al., 2014).
4. Increases norepinephrine and dopamine, improving mood, focus, and energy (Huttunen et al., 2004; Huberman, 2023).
5. May help with chronic pain and mental resilience through controlled exposure to stress.

When to Do Cold Exposure
1. Morning: best for energy, focus, and setting a healthy circadian rhythm.
2. After training: useful for faster recovery, but not ideal if muscle growth is the goal, as it can blunt hypertrophy.
3. Evening: can be calming if mild and short, but strong cold exposure too late may delay sleep for some people.

Cold Exposure Is a Stress - and the Real Practice Is in the Mind
Cold exposure is a controlled stressor. It’s not about fighting the cold but learning to relax into it. Through breathing, focus, and acceptance, you train your nervous system to stay calm in discomfort - a skill that translates far beyond the ice bath.

If you are curious to try out ice bathing in Munich are welcome to join our Next Ice Bathing Session!

Our first guided Mindful Warriors Ice Bathing Session takes place on Saturday, 09 November 2025 at the Isar, Munich - including guided breathwork, cold immersion, movement, and tea & talk together afterward - usually it will happen once a month.