Is Cold Plunging Healthy?

Whether cold plunging is really healthy is probably one of the most frequently asked questions when it comes to stepping into ice-cold water. And it’s a controversial topic. While many experienced cold plungers swear by the positive effect on health and well-being, some scientists argue that there have not yet been enough studies to clearly describe cold plunging as beneficial to health.

In this article, we present various study results that take a closer look at the various health effects of cold plunging. We also have separate posts on the benefits of cold plunging and the risks and side effects, which provide a broader overview.

Strengthening the Immune System

Cold plunging is often described as a real booster for the immune system. Many believe that regular exposure to cold water strengthens immunity and helps prevent infections.

Some scientific evidence supports this idea:

• In 1996, Czech scientists published the results of their study in which they investigated the effect of cold plunging on the immune system of young, athletic men. Interestingly, there was hardly any effect on the participants’ immune system immediately after stepping 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 2016 study on hot-to-cold showers examined the effects of cold plunges on health, quality of life, and productivity at work. 3,000 participants between the ages of 18 and 65 took cold showers for 30 days and then reported that the number of sick days fell by 29%.
• A 2014 study looked at the connection between cold plunging and upper respiratory tract infections. For 13 weeks, 44 couples were examined: The participants included 21 cold plungers and 23 pool cold water swimmers, and their partners, who did not get into the water at all during the study. Results showed no clear protective effect against respiratory infections, but cold plungers reported fewer illnesses than their partners.

In summary, regular practice seems more important than one-off plunges when it comes to immune benefits.

Stress Tolerance and Oxidative Stress

The phrase “What doesn’t kill you makes you stronger” fits cold plunging perfectly. Repeated cold exposure seems to build resilience.

Science has also looked into the question of whether the body can achieve increased stress tolerance, for example, against illness, through cold plunging or cold water swimming.

A 1994 study suggests that this may well be the case. Ten healthy cold plungers were examined before and after cold plunging, 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 cold plungers, which can be seen as a mechanism of hardening.

Cardiovascular Effects

A Greek study (2019) found that winter swimming can have a hardening effect on the cardiovascular system if it is practised in good health. At the same time, the scientists emphasize that cold water swimming can also be life-threatening for people with cardiac illnesses or inexperienced swimmers.

Important: People with cardiovascular disease should avoid cold plunging without medical approval.

Circulation and Heat Balance

When exposed to extreme cold, blood vessels contract, pushing blood toward vital 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 cold plungers, such as faster rewarming and improved blood circulation of 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

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. Cold plunging 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 do cold plunges have on the heart and blood vessels of a healthy person? A 2015 study examined this: 10 experienced cold plungers 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. From this, the scientists concluded that exposure to cold can influence oxidative stress markers. The study results also indicated a positive effect of cold adaptation on cardioprotective mechanisms.

Cold Plunging and Diabetes

Diabetes sufferers are advised against jumping into cold water. Interestingly, there appears to be a connection between cold plunging and the body’s sensitivity to insulin, which could benefit diabetics (after consulting their doctor). Norwegian scientists examined 104 studies and found that cold plunging reduces insulin resistance and increases insulin sensitivity.

Anti-Inflammatory Effects

In addition to the health benefits already mentioned, cold plunging and cold water swimming have an anti-inflammatory effect. This assumption is partly because a cold shock activates 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 cold plunges (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 (2008) backed the same findings on the connection between exposure to cold and increased cortisol levels. The study found that the cortisol concentration in the blood of the experienced cold plungers in the test group was significantly higher than that of the inexperienced test subjects. Scientists therefore concluded that regular cold plunging leads to 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 related to the fact that cold therapies are often used in (competitive) sport. Since 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. In competitive sports, micro-tears can occur in the muscles, from which the body can recover quickly.

This is exactly where cold therapy (cryotherapy) 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. Benefits: The cold helps relieve pain, reduces swelling in injuries, and reduces muscle tension.

And how do scientists assess the presumed positive connection between cold and regeneration after sport?

• A 2014 study concluded that stepping 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. This raises the question of what role psychological effects (placebo effect) play in cold plunging or cold exposure.
• A 2017 study examined the theory that cold plunging reduces inflammation in the skeletal muscles. The study investigated how nine male test subjects regenerate after engaging in physical activity in various environments. One day, the men immersed themselves in 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. Therefore, the positive effect of cold plunging 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 cold plunge on recovery from muscle damage after exercise. It found that the cold plunge shortens recovery time and alleviates pain.
• Cold-water immersion for athletic recovery: One size does not fit all by Halson (2014): The study found that individual tolerance to cold, duration, and temperature of the cold plunge help in 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 cold plunging versus active recovery on inflammation and cell stress responses in human skeletal muscle after resistance exercise. The results indicate that a cold plunge leads to a lower inflammatory response and cell stress response in the body.

Cold Plunging and Cancer

Some studies suggest that cold therapy can help cancer patients by reducing inflammation, easing pain, and improving well-being during treatments like chemotherapy.

• 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 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.

Cold Plunging Effect on Body Fat

The cold melts pounds! The aforementioned Norwegian study examined 104 scientific research results on cold plunging and cold water swimming. The study found that cold ice-cold water immersion leads to a reduction and/or transformation of body fat tissue, contributing to weight loss.

Cold activates brown fat in the body, which, unlike “bad” white adipose tissue, burns calories to maintain body temperature. This, in turn, acts as a protective factor against diabetes and cardiovascular disease. Scientists predict potential in cold plunging as a “health prophylaxis”.

Increased Well-Being

Many cold plungers report that regular cold plunging makes them feel better in everyday life. A Finnish study (2004) found that cold water swimming increases general well-being. From October to January, people who regularly swam in cold water were asked about their well-being. 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 cold water swimming.

Mental Strength

Getting into icy water requires mental discipline. When exposed to cold, the body reacts with a cold shock. Studies on the Wim Hof Method (2018) show that breathing and meditation techniques combined with cold exposure allow the brain to regulate body responses, proving that cold plunging strengthens both body and mind. Cold plunging, therefore, strengthens not just the body, but also the mind in everyday life.

Depression Relief

The phrase “cold plunging makes you happy!” is often heard from convinced cold plungers. Cold plunging also releases endorphins and adrenaline, which explains why many report feeling euphoric afterward. Early research suggests that cold exposure may help alleviate depression and anxiety, even reducing the need for medication in some cases.

• A 2008 scientific article found 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 looked at a woman who had suffered from severe depression and anxiety since her youth. 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.

Community Experiences on Cold Plunging

Our community members often highlight the mental benefits of cold plunging: increased stress resilience, inner balance, and improved mood. Some report physical improvements too, including better skin health, reduced migraines, and even relief from psoriasis. The fact that cold plunging generally makes you less susceptible to colds is another point that some members of our community would agree with.

We have not received any worrying reports or bad health experiences with cold experiences. Rare negative effects can include: exhaustion, headaches, or worsening of Raynaud’s syndrome. Most of these seem linked to staying in too long or water that’s too cold.

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 for as long as you feel comfortable.