Ice baths and other forms of cold exposure have been used for health reasons since ancient times, and more recently the specific idea of cold showers has become popular for its positive effects on mood, energy and the immune system.
For much the same reasons it’s an important part of the Wim Hof Method, where it is combined with breathwork exercises.
After reading the article on this site about the Science of the Wim Hof Method Breathing Technique, many people asked me to write up something similar about cold exposure. So below is the list of 12 health benefits and other nice effects of ice baths and cold showers – complete with some details of what, scientifically, is happening within the body.
- Improve Cardiovascular Health & Resting Heart Rate
- Learn to Control your Breathing under Stress
- Boost Metabolism
- Clear your Mind
- Feel Warmth after Stepping out
- Better-Looking Skin
- Boost your Mood (and Combat Depression)
- Sleep more Easily
- Improve Attention and Alertness
- Boost your Immune System
- Increase your Tolerance to the Cold
- Extend your Healthy Lifespan
Note that some of the effects relate to certain temperature ranges, and some happen instantly, while others become significant only after a longer experience with the cold.
And while cold water can be a useful tool – if abused it can be dangerous, especially if you stay too long (afterdrop and hypothermia), have too much contact with ice (ice burns and frostbite) or have underlying health conditions. So take care and be healthy!
1: Improve Cardiovascular Health & Resting Heart Rate
As soon as your skin touches the cold water, many systems in your body begin to work hard to prevent you from losing valuable internal heat. It doesn’t realize that we can just turn the shower off or climb out of our bathtub! It’s acting as if we had gotten lost in the cold while out hunting and don’t know for how long we’ll be exposed.
The most noticeable effect is that all the blood vessels near your skin contract – from the major veins to the capillaries – to keep the warm blood inside where our internal organs need the heat. On the other hand when you’re very hot, these vessels dilate to help you lose this heat as quickly as possible.
These blood vessels are made of muscle – smooth muscle as opposed to skeletal muscle like your biceps, or heart muscle – and all of these can be trained to be fitter with the right sort of exercise:
- Skeletal Muscle: regular exercise like weightlifting, running or calisthenics
- Heart Muscle: “cardio” exercise like running, cycling or rowing
- Smooth Muscle: switching between heat and cold
So a clear benefit of cold showers is in training these smooth muscles. This useful both to athletes and to people anticipating heart disease later in life. You can’t flex and admire your smooth muscles like the biceps, but experienced cold bathers often report a lower resting heart rate – a measurement correlated with cardiovascular health.
Some people even take this a stage further by switching a few times between hot and freezing cold – contrast bathing – although to improve your tolerance it’s best to always finish with cold.
Please note however that if you’re not used to cold exposure or symptoms of heart disease then the stress of this training might be too much for your body. Please be careful and know your limits!
2: Learn to Control your Breathing under Stress
Your body’s natural response when entering freezing water is to panic, shiver, and breathe too rapidly and shallow. This is because your sympathetic nervous system gets activated very strongly, preparing you to escape the cold environment ASAP. It assumes that there’s some emergency, like we’ve just fallen into a icy mountain river!
However with practice you can train your breathing to be slow and deep despite the stressor. This activates the parasympathetic nervous system that allows us to rest and relax. The sympathetic nervous system is great, but if you often feel overwhelmed by things, cold showers can teach your body to react less.
Specifically for ice baths and cold showers, you should be able to avoid shivering if you breathe in the right way and don’t stay in for too long.
3: Boost Metabolism
Realizing that it might need to produce lots of extra energy to start warm, your metabolism increases massively upon entering cold water. This effect is especially strong upon entering water beneath about 16°C. Scientists experimented with three temperatures of bath and their results were:
- 32°C: no change in metabolism
- 20°C: jumped by +93% (nearly doubled)
- 14°C: jumped by +350% (more than quadrupled)
So whether you prefer a faster metabolism to help maintain a healthy weight, or so your body repairs itself faster, you may benefit from an ice bath or cold shower.
4: Clear your Mind
If your mind is often wandering, various kinds of mindfulness meditation can help. However this almost comes for free with an intense experience like an ice bath as it’s difficult to think of anything else! Then you’ll step out of the water with a clearer mind than when you went in.
5: Feel Warmth after Stepping Out
One of my favourite things about taking cold showers is the feeling of warmth after stepping out of the water. It’s counter-intuitive, but on a cold day, an effective way to feel warm is to have a hot shower, finishing with 30-60 seconds of the coldest water your shower will give you.
The reason this keeps you warm is two-fold. Firstly we’ve already seen how the metabolism increases during cold exposure.
But secondly, your body may invoke another defense mechanism called the Hunting Reaction, designed to protect your skin and extremities from frostbite after (or sometimes during) cold exposure. Some minutes after entering freezing water, the capillaries near the surface of the skin may suddenly dilate and allow warm blood to reach the surface again where you feel it.
6: Better-Looking Skin
Hot water can dry out your skin because it strips out the natural oils. You can avoid this by washing your face in cool or lukewarm water, and avoiding washing it too long with hot water.
However taking this a stage further with icy cold water doesn’t seem to have any additional benefits!
7: Boost your Mood (and Combat Depression)
You only have to try one cold shower or ice bath to see the positive effect on your mood afterwards! From a biochemical perspective, emotions are governed by various chemicals in the brain such as serotonin and noradrenaline. Depression in particular has been strongly linked to these.
A major effect of cold exposure is that it massively increases noradrenaline levels – although only when the water is colder than about 16°C. A 10°C bath will have a much stronger effect than a 20°C bath.
Another reason is that inflammation is reduced by cold exposure. Inflammation in the brain blocks the transmission of chemicals related to mood, including serotonin. Ice baths and deeply cold showers therefore can mitigate this.
8: Sleep more Easily
There is some disagreement about whether cold showers help you sleep. We’ve seen that cold water causes a burst of noradrenaline, which increases heart rate and energy production. This isn’t exactly the best thing before sleep!
But on the other hand, reducing your body temperature prepares your body to sleep.
So if you’re in a hot environment then taking a cool shower (but not much colder than 20°C) can help you sleep. But if you take an intense freezing shower just before bed then it might just keep you awake!
9: Improve Attention and Alertness
Just as noradrenaline helps with your mood, it also boosts your concentration and cognitive ability. So again, as long as your shower is cold enough, you may enjoy a short-term improvement in brainpower!
10: Boost your Immune System
The way cold exposure boost the immune system is complex, but there are some things we do know. Winter swimmers, cold shower devotees, and half of Finland will tell you that cold bathing reduces how often people get common illnesses such as seasonal flu – but as well as anecdote, there are studies that provide concrete evidence for this.
Scientific research on the mechanisms for this are hard to find, but one likely mechanism is white blood cell production caused by the adrenaline release that you get during the cold shower.
On the other hand, if your body is already fighting a disease, the cold can actually be an unwelcome stress. For some illnesses such as fevers, the body heats itself up to kill (“denature”) the virus. Cold showers – especially long ones – hinder its ability to do this.
And for head-colds, UTIs, and other infections of the skin or extremities, the cold makes the blood vessels contract around exposed parts of your body, which obviously hinders the body’s ability to deliver the disease-fighting white blood cells to the affected area.
11: Improve your Tolerance to the Cold
Many anecdotes from people who regularly subject themselves to the cold (outdoor workers in cold environments, Winter swimmers, Wim Hof practitioners, etc.) will tell you that they feel the cold less than other people.
One explanation for this that has been suggested is that the heat-producing Brown Adipose Tissue (“brown fat”) increases with repeated exposure to the cold. This has recently been cast into doubt by studies comparing Wim Hof (who is very experienced with the cold) and his twin brother (who is not). Both reported similar levels of brown fat and of cold thermogenesis.
However it is clear that with the correct training, people such as Wim Hof have been able to do impressive feats, such as bathing in a container of ice for more than an hour!
12: Extend your Healthy Lifespan
Many diseases in old age are caused or exacerbated by chronic inflammation. This is where inflammatory proteins swarm around the body even when there’s no threat or injury for them to remedy. The noradrenaline released during deep cold (that is, beneath 16°C) has yet another beneficial effect in reducing this dangerous inflammation.
Further Information
If you have any comments or questions about this article, you can contact me by email.
I was personally introduced to cold showers and ice baths through the Wim Hof Method – which also combines breathwork and balance exercises to make you (to quote Wim himself) “happy, strong and healthy”, including the advanced technique of thermogenesis.
Read here for some very informative analysis from Rhonda Patrick about cold water exposure.
To determine how much ice you need for an ice bath – check out my online calculator.
Read here for information about the Science of the Wim Hof Method breathing technique.
And finally, should I take a cold shower after my workout?