Cold showers and cold immersion have been popularised by the like of Wim Hof and have become a key part of many peoples routine. Here is the low down on cold showers. Look forward to you sharing your stories and thoughts in the comments section.
If you want to know even more I recommend any of Wims books and resources and how cold immersion fits into his wider approach to health and performance.
Better to take cold showers
We live in a very controlled environment, house heating and cooling, office heating and cooling and even heated cars. We spend most of our time within a fairly limited range of temperatures. This, of course, wasn’t how we evolved, in a more primitive setting Heat is relatively easy to escape from by finding shade or cool water.
A temperature drop is another key signal and enabler to good sleep alongside the more commonly known melatonin trigger brought on by decreased light and changes to the colour spectrum at the end of the day (the reason for the commonly found blue light filter options on many mobile devices).
Without fire however cold is more difficult to escape from. We evolved being exposed to much larger temperature variations and more cyclic temperature changes each day. Cold mornings, rising midday temperatures and then plunging temperatures as the sunset and night approached.
Even after humans learnt to craft and manage fire, often the blazing heat would diminish through the night in an unmanaged fire as those huddled around the fire slept.
Unless you work largely outdoors cold showers might be your only opportunity to stimulate your body and expose your physiology towards maintaining and building its inherent capabilities.
Cold showers stimulate circulation and regular cold shower/cold immersion is reported to improve skin and hair condition as well as improving general health and wellness (avoiding colds, flu etc.)
Can cold showers be bad for you?
The ‘shock’ effect could have a detrimental effect on anyone with underlying cardiovascular issues. It’s probably not a good idea to take cold showers (or cold immersion) without medical advice and supervision. Medical conditions such as hypertension, stroke, cardiac issues would raise concern. Seek professional medical advice.
How long should you shower for?
Cold showers are more popular than the cold baths or ice baths often seen in workshops or in Youtube demonstrations, the key reason being the convenience of cold showers. Not everyone has the time, will or means to fill up a large bath of ice each day for a 2-5 minute immersion.
No need for a marathon cold shower to achieve the benefits which largely come from the initial ‘cold shock’ and cooling that occurs in the first minute or two. My goto method is to stand in the shower ahead of turning on the water which gives me 60 seconds or so of cold shower ahead of warming up. From a practical perspective, I find hair shampoo etc is less effective in cold water. I’ve yet to experiment further with avoiding shampoo and relying just on the water to cleanse.
The science of cold showers
Cold showers essentially instantly shock your senses – and cause the odd swear word in anyone not used to an instant cold shower! This shock impact both the body and mind. The mind receives a mass of input from nerves all around the body. The skin is our biggest organ and has a mass of nerve endings which all send signals to the brain in response to the sudden cold.
This ‘sensory overload’ creates a great focus in the mind, just trying thinking about something else when the cold water hits. In contrast to a warm shower where your thoughts are usually wandering aimlessly, essentially being physically in the shower, but mentally in the office, paying the bills or caught up in some other story. A cold shower might be the ultimate safe single-pointed meditation!
Physically the initial response to the cold water, especially in the first week or so of trying cold showers, is usually a couple of either forced inhalations or exhalations. This can be followed by a time of short shallow breaths, close to hyperventilation. As cold showering becomes a regular habit, both these effects diminish. Well seasoned cold warriors such as Wim Hof have incredibly relaxed breath control.
Our vascular system constricts in response to the cold water, prioritising blood and oxygen delivery to essential organs. The image below from Human Physiological Responses to Cold Stress and Hypothermia illustrates this effect in the before (left) and after (right) thermal images.
White and brown fats
Fat is essential to our functioning. In terms of cold showers, claims are made that cold showers reduce white fat, white fat is the fat that accumulates around the abdominal area and contributes to metabolic issues. White fat is linked to increased risk of cardiovascular issues, diabetes and cancer.
Brown fat is fat that is more readily used for fuel and gains its colour from stored iron and the multitude of tiny blood vessels. Brown fat is used by the body to produce heat. We need this brown fat to maintain our (relatively) high body temperature.
So how does cold showering impact our fat type? Our body has a continuous choice of how to use or store energy, brown or white. One theory is that as we live in an artificially warmer environment our body needs to tap into the brown fat reserves less often, so develops a bias towards white fat storage. The cold shower shock stimulates the body into storing brown fat ‘just in case’ it needs to warm us. A cold shower each day is a little like doing 20 press ups each day, our body starts to pre-prepare for the demand we will put on it.
Another benefit of this adaptation towards brown fat as an energy source is to help balance and maintain our metabolism and energy levels. Combining cold showers and intermittent fasting sounds like it could be a health panacea, we will leave that for a future post!