Whether ice bathing is really healthy is probably one of the most frequently asked questions when it comes to jumping into ice-cold water. And this is a controversial topic. While many experienced ice bathers swear by the positive effect on health and well-being, some scientists argue that there have not yet been enough studies and thus substantiated evidence to describe ice bathing as healthy or even beneficial to health. In this article, we present many different study results that take a closer look at the various health effects of ice bathing. We also have separate posts on the health benefits of ice bathing as well as the risks and side effects of ice bathing, which will also give you a good overview.
Table of contents
The positive aspects that are often mentioned in connection with ice bathing are manifold. Basically, a distinction can be made between effects on physical and mental health. Ice bathing is said to bring about changes in bodily functions, but also in the psyche.
Strengthening the immune system and protecting against infections
Ice bathing has a reputation as a real booster for the immune system. It is said that those who regularly step into ice-cold water strengthen their immune system and thus protect themselves against infections. In fact, there is some scientific research that at least suggests that ice bathing has a positive effect on the immune system. In 1996, Czech scientists published the results of their study in which they investigated the effect of ice bathing on the immune system of young, athletic men. Interestingly, there was hardly any effect on the participants’ immune system immediately after going into the ice water, but positive changes were observed over a longer period of time (three times a week for six weeks). The repeated exposure to cold created stress-inducing, non-infectious stimuli for the body, which activated the immune system of the study participants to a small extent. If you want to strengthen your immune system, regular ice bathing therefore seems to be of central importance.
A recent study from 2016 looked at the topic of alternating showers (switching from hot to cold) and examined its effects on health, quality of life and productivity at work. A good 3,000 participants between the ages of 18 and 65 took cold showers for 30 days and then reported on their experiences. The most important result of the study was that the scientists who conducted it found that the number of sick days within the participant group fell by 29%.
In 2014, another study looked at the connection between ice bathing and upper respiratory tract infections. For 13 weeks, 44 couples were examined: The participants included 21 ice bathers as well as 23 swimmers who only swam in the pool and their partners who did not get into the water at all during the study. The ice bathers fell ill less than their partners, but there were no significant differences between the ice bathers and the swimmers in terms of the number of upper respiratory tract infections. On the other hand, the documented illnesses among the ice bathers were even higher than among the swimmers. In summary, the scientists were unable to attribute any protective effect against upper respiratory tract infections to ice bathing.
Less oxidative stress and higher stress tolerance through regular ice bathing
What doesn’t kill you makes you stronger! When it comes to ice bathing, it’s hard to avoid the statement that ice-cold water hardens the body. Science has also looked into the question of whether the body can achieve increased stress tolerance, for example against illness, through ice bathing or winter swimming.
A scientific study from 1994 suggests that this may well be the case. Ten healthy ice bathers were examined before and after ice bathing and several physical changes caused by the cold exposure (e.g. the uric acid concentration in the plasma of the study participants), which indicate an increase in stress tolerance, were documented. The scientists observed an adaptation to repeated oxidative stress in the ice bathers, which can be seen as a mechanism of hardening.
Strengthened cardiovascular system
A Greek study from 2019 also states that winter swimming can have a hardening effect on the cardiovascular system, among other things, if it is practised in good health. At the same time, the scientists emphasize that ice swimming can also be life-threatening for people with (cardiac) illnesses or inexperienced swimmers. A slow approach and good acclimatization are the be-all and end-all when ice bathing, so that this sporting activity with health-promoting potential does not become a life-threatening undertaking.
Improve blood circulation and heat balance
In extreme cold, the blood vessels contract. Circulation is stimulated as the body begins to pump blood towards the organs to protect them from the cold. This generates warmth, which you feel pleasantly throughout your body shortly after getting out of the ice water. In terms of heat balance, scientists have observed long-term adaptation processes in ice bathers, such as faster rewarming of the extremities. Ice bathing also appears to help improve blood circulation in the extremities. Over time, the body learns to react better to temperature stress and you no longer cool down so quickly.
Fewer heart and vascular diseases
The above-mentioned vasoconstriction during exposure to cold increases blood pressure, which means that the heart has to work against a higher pressure. In ice water, the blood is also shifted from the arms and legs to the heart, which requires additional work from the heart. Consequently, ice bathing is in many ways a moment of shock or a state of emergency for the heart, which is why people with cardiovascular diseases should urgently stay away from ice-cold water – otherwise they risk an undersupply of the heart muscle, which in the worst case can lead to a heart attack.
But what effect does ice bathing have on the heart and blood vessels of a healthy person? This question was the subject of a 2015 study in which 10 experienced ice bathers and 16 people not used to the cold were examined. Differences between these two groups were found in apolipoprotein levels, homocysteine levels and T3 (triiodothyronine) levels, among other things. From this, the scientists concluded that exposure to cold can influence oxidative stress markers. The study results would also indicate a positive effect of cold adaptation on cardioprotective mechanisms. In other words, going into ice water could have a protective effect on the heart in healthy people.
Ice bathing and diabetes
In addition to people with cardiovascular diseases and high blood pressure, diabetics are also warned against jumping into cold water. Interestingly, there appears to be a connection between ice bathing and the body’s sensitivity to insulin, which could benefit diabetics – after consulting their doctor, of course. Norwegian scientists who examined 104 studies on the subject of ice bathing found that ice bathing reduces insulin resistance and increases insulin sensitivity.
Anti-inflammatory effect due to temporary increase in cortisol levels
In addition to the health benefits already mentioned, ice bathing and winter swimming are also said to have an anti-inflammatory effect. This assumption is partly due to the fact that a cold shock activates so-called corticoids in the body, a group of steroid hormones that slow down inflammatory processes. In a self-experiment conducted in 1992, a group of German students and their teachers investigated the effect of regular ice baths (at least once a week, 2 to 10 minutes per ice bath). The blood samples showed a significant increase in cortisol (a stress hormone from the glucocorticoid group) in the body in the first 30 minutes after exposure to cold, after which the cortisol level dropped again.
A Finnish study from 2008 came to similar conclusions with regard to the connection between exposure to cold and increased cortisol levels. Of particular note in this study is that the cortisol concentration in the blood of the experienced ice bathers in the test group was significantly higher than that of the inexperienced test subjects. This leads the scientists to assume that regular ice bathing leads to so-called adaptive mechanisms in the body, i.e. the body adapts through regular exposure to cold.
Regeneration after sport and pain relief
The assumption that exposure to cold can alleviate inflammation in the body is certainly related to the fact that cold therapies are often used in (competitive) sport. After all, if inflammatory processes can be slowed down or prevented, recovery after sport is generally quicker. In a wide variety of sports, the body is put to the test and really strained. Micro-tears can occur in the muscles, from which the body first has to recover – especially in competitive sports, the recovery phases are usually quite short.
And this is exactly where cold therapy, also known as cryotherapy (Greek kryo = cold), comes into play in many cases. A strong cold stimulus, which can be applied locally to certain areas of the body (with special devices) or to the whole body (in an ice hole or cold chamber), is intended to activate the body’s anti-inflammatory powers and slow down inflammatory processes. At the same time, the cold is said to relieve pain, reduce swelling in injuries and reduce muscle tension. Most of us are familiar with the idea of applying an ice pack to the affected area after an injury.
And how do scientists assess the presumed positive connection between cold and regeneration after sport, specifically using the example of winter swimming? They certainly leave room for doubt. A study from 2014 came to the conclusion that going into cold water after a sporting performance does not bring any greater benefits than the placebo effect. In the study, 30 men recovered after an intensive sporting performance in three different environments: Cold water immersion (10.3°C ± 0.2°C), cold water immersion-placebo (34.7°C ± 0.1°C) and thermoneutral water immersion (34.7°C ± 0.1°C). The first two groups (cold water/placebo) showed better results in terms of movement, pain and strength than in warm water. This raises the question of what role psychological effects (placebo effect) play in ice bathing or cold exposure.
Another study from 2017 looks at the theory that bathing in cold water reduces inflammation in the skeletal muscles. The study investigated how nine male test subjects regenerate after sporting activity in different environments. On one day, the men went into cold water at 10 degrees Celsius for 10 minutes after exercising. On another day (with at least a week’s interval from winter swimming), the subjects cycled at a slow pace for 10 minutes. Muscle biopsies were taken before and after training to document changes in the body. No significant differences were found between the two regeneration measures. So here too, the positive effect of ice bathing on regeneration after sport could not be scientifically confirmed.
The Effect of Cold Water Immersion on Recovery from Exercise-Induced Muscle Damage by Vaile, et al. (2008): This study examined the effects of ice baths on recovery from muscle damage after exercise. It was found that the ice bath shortens recovery time and alleviates pain.
Cold-water immersion for athletic recovery: One size does not fit all by Halson (2014): This study looked at the effectiveness of ice baths in the recovery of athletes. The results show that individual tolerance to cold and the duration and temperature of the ice bath have a positive effect on recovery.
The effects of cold water immersion and active recovery on inflammation and cell stress responses in human skeletal muscle after resistance exercise by Roberts, et al. (2015): This study investigated the effects of ice baths versus active recovery on inflammation and cell stress responses in human skeletal muscle after resistance exercise. The results indicate that an ice bath leads to a lower inflammatory response and cell stress response in the body.
Ice bathing for cancer
Especially with regard to inflammation and pain relief, ice baths can be helpful in the context of cancer and associated treatments such as chemotherapy and radiation. Some studies show that cold applications such as ice baths can reduce inflammation in cancer patients. For cancer patients, ice bathing may also improve mental health and quality of life.
Whole-Body Cryotherapy in Breast Cancer Patients: Effects on Quality of Life and Symptoms by Wojtyna, et al. (2018): This study investigated the effects of whole-body cryotherapy on quality of life and symptoms in breast cancer patients. The results show a significant improvement in terms of physical symptoms and mental health.
The effect of cold-water immersion on muscle soreness and subjective well-being in cancer patients: a randomized trial by Jegede, et al. (2020): This study addressed the question of whether cold exposure (at a temperature of 10°C) can improve muscle soreness and well-being in cancer patients. The results show that exposure to cold can lead to a significant reduction in muscle soreness symptoms and an improvement in subjective well-being.
Effects of whole-body cryotherapy on serum mediators of inflammation and serum muscle enzymes in cancer patients: a preliminary report by Stanek, et al. (2011): This study investigated whether whole-body cryotherapy (at temperatures of -110°C to -140°C) can relieve inflammation and muscle pain in cancer patients. During the study, the therapy resulted in significant improvements in inflammatory markers and muscle enzymes.
Ice bathing converts body fat into energy
The cold melts pounds! Ice bathing helps with weight loss, as confirmed by the aforementioned Norwegian study, which looked at a total of 104 different scientific papers on ice bathing and winter swimming. While the Norwegians remain rather vague in many of their statements on the health benefits of ice bathing, they clearly emphasize that going into ice-cold water leads to a reduction and/or transformation of body fat tissue. Cold activates the so-called brown fat in the body, which – in contrast to “bad” white adipose tissue – burns calories to maintain body temperature. This in turn can be seen as a protective factor against diabetes and cardiovascular disease, so that the scientists see potential in ice bathing as a “health prophylaxis”.
Increased well-being in everyday life
Many ice bathers report that regular ice bathing makes them feel better in everyday life. The fact that winter swimming increases general well-being was actually confirmed in a Finnish study in 2004. From October to January, people who regularly swam in cold water were asked about their well-being. While in the first few weeks of the test period no increase in well-being could be documented compared to non-swimmers and swimmers were even diagnosed with illnesses 50% more frequently, the differences were clearly visible after 4 months. The swimmers felt more energetic and active than the non-swimmers. Swimmers with asthma, rheumatism or fibromyalgia also reported pain relief from winter swimming.
Training mental strength – brain over body
Anyone who has ever practiced ice bathing knows exactly how much effort it takes to get into the icy water. When exposed to cold, the body reacts with a cold shock (e.g. the heart rate and blood pressure increase) and it is important to overcome this shock with mental strength and to signal to the body that it is not in an emergency situation. In the so-called “Brain over Body” study from 2018, scientists took a closer look at the Wim Hof method to understand whether the brain can control the body’s reactions. They came to the conclusion that the techniques used by Wim Hof (forced breathing, meditation, exposure to cold) do indeed put the brain over the body. Ice bathing therefore appears to strengthen not only the body, but also the mind. And you benefit from this not only in the ice hole, but also in everyday life.
Relief from depression
“Ice bathing makes you happy!” This sentence is often heard from convinced ice bathers. Ice bathing releases adrenaline and endorphins – both hormones that make you feel euphoric after an ice bath. The feeling of happiness lasts all day, but what many people don’t know is that endorphins have a positive effect on depression. So could ice bathing also have a positive long-term effect on the psyche? Several studies have looked into this.
In a scientific article from 2008, the thesis was put forward that regular cold showers can work as a therapeutic measure against depression. Exposure to cold activates the sympathetic nervous system and increases the blood levels of beta-endorphin and noradrenaline (so-called happiness hormones). Initial trials with a small test group actually showed that cold water therapy can alleviate depressive symptoms quite effectively and without significant side effects – science should devote more attention to this topic, the study leaders concluded.
A scientific report from 2018 about a woman who had suffered from severe depression and anxiety since her youth is particularly exciting. After the birth of her daughter, the woman insisted on medication-free treatment, which led to the initiation of cold water therapy (swimming). The result is astounding: immediately after swimming in the cold water, the woman’s mood was immediately brightened and her symptoms of depression gradually decreased, so that medication could be reduced and eventually discontinued. At the follow-up examination one year later, the woman was also completely off medication.
And what does our community say? Is ice bathing healthy?
Our ice bathers generally rave about the health benefits of ice bathing. The positive effect on mental health is particularly often emphasized: They say that going into the cold water makes you more stress-resistant and inwardly balanced. Many also see ice bathing as a good way to train mental strength. But some ice bathers are also concerned with their physical health. There are reports from our community that ice bathing has positively supported the treatment of migraines or even heavy metal poisoning. For some ice bathers, the appearance of their skin has also improved significantly and even psoriasis has disappeared. The fact that ice bathing generally makes you less susceptible to colds is another point that some members of our community would agree with.
We have not received any particularly worrying reports or bad experiences with ice bathing in terms of our own health. Exhaustion, colds, headaches or visual disturbances are some of the negative reactions that have occurred after going into the icy water – although these often seem to be related to the water temperature (= too cold) and/or the duration of the ice bath (= too long). Raynaud’s syndrome, which can lead to color changes in one or more fingers, is another side effect experienced by some members of our community – neoprene socks and gloves can be helpful here.
In summary, the health benefits of our ice baths outweigh the risks. As going into the icy water is very challenging for the body (and mind), you should only do it if you are in good health. People with pre-existing medical conditions should seek medical advice beforehand. And if you then stay in the ice water: Listen to your body and only stay in the water as long as you feel comfortable.
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