Cold Water Immersion

Humans have a fear response.  When we face a threat, whether actual or perceived, our bodies respond by getting us ready to fight or run away.  Our hearts start racing, we breathe faster, our muscles contract and all of the blood from our extremities are pumped to our vital organs. We get pale, we feel cold and numb and our minds don’t work as well as they should because; well, it doesn’t help you much if you can solve an algebra problem while the angry lion eats you.  This is great when angry lions are chasing us but it certainly doesn’t serve us when the threat is perceived.  Unfortunately, we can’t reason with our bodies when experiencing a perceived threat; we can’t convince it that there isn’t actually anything chasing us.  It’s just our fast paced lives, our participation in the modern rat race called life.

Although we cannot reason with our bodies we can definitely train them.  In order to train your body to control your fear response, you need to put yourself in an actual threatening situation and train your body to remain calm.  You need to face the threat while keeping your breathing under control and your heartrate low until your body can realise that you are not in any real danger.  Once you reach this point, you can relax deeply, think clearly and reap the benefits of this calm space.

Cold exposure can be a safe way to train yourself to control your fear response.  As always, find what works for you and ensure you read up on the risks before deciding to do this yourself.


I could not see myself jumping into my pool in the winter a year ago but this is something I do at least twice a week now. It’s definitely daunting at first but if you expose yourself to a cold plunge regularly it becomes a relaxing and an exhilarating experience, one that you start to crave.  I started small, a year ago and I have worked myself up to a cold plunge after a year.  I take a cold plunge these days after most of my sauna sessions and plan on doing this throughout the winter.  The colder the better.

During last winter I took on a challenge from a friend to take cold showers in order to improve my immune system and avoid getting the flu.  I started this practice by ending my normal showers with one minute under cold water which is all I could face at the time.  I increased the cold part of my shower to two minutes, then three then took my entire shower in cold water.  I took my time between each step, spending a week or two on a minute cold shower and moving to two minutes for another two weeks or so.  It was only after doing this for a few weeks that I started experiencing the fear of the cold water becoming less and less every time but I was not exactly sure what this meant at the time, my main focus was to prevent the flu that winter.

After a month or two of cold showers, I came across an Instagrammer @leighewin who explains how to control your fear response beautifully; his was the first connections I made with, what I now know to be, the most important benefit of cold exposure to me.  Learning to control my fear response.

How I do this is to extend my out-breath by breathing out as slowly as possible and by keeping my body as relaxed as possible while standing under the cold shower or sitting inside the cold pool.  I started with putting one limb under the cold water at a time, then my stomach, back and head.

When moving over to a cold plunge I was already used to the cold exposure but I still took it one step at a time.  I got used to it quite soon and I am able to take a plunge into the icy water straight away now.  Avoid putting your head under icy water when you are starting out and if you are alone.  But once you are used to the experience the cold water on your face wakes you up like nothing else.  When taking a cold plunge I avoid putting my hands under the water, I found that I could stay under for longer if my hands were above the water.    Studies show that water temperatures should be 15°C or colder for you to achieve a physiological response.  During this winter my pool reached temperatures as low as 9°C.

I feel like a million bucks when I get out from my cold plunge and the feeling lasts the whole day.

If you want to try this yourself, it’s important to make sure that you are safe, so start one step at a time and if the water temperature is below 13°C you should have someone with you just in case you need help getting out.  Never get into a cold plunge if you feel panicked, this could lead to drowning.


There are also a range of other benefits to cold showers and cold immersion:

  1. Build a strong immune system.

I have not even had the sniffles this winter despite being around various family members and colleagues at work who were ill.  In the past I was susceptible to contracting the flue during the change in season and it was a welcome victory not to fall ill this winter. The minor discomfort was definitely worth it!

Cold water immersion has been shown to increase metabolic rates because it causes shivering and activates your immune system. Experiment participants who participated in six weeks of immersions benefited from an increase in plasma concentration, as well as T helper cells and lymphocytes which are all key to strong immunity.

  1. Ease stress and may relieve depression.

Cold Water Immersion stimulates the release of certain neurotransmitters.  These are the chemical messengers that regulate countless functions and processes in your body, from sleep to metabolism.

By stimulating norepinephrine release into the parts of the brain where focus, attention and emotions are controlled [4], cold exposure can reduce stress and improve mood. Research found that depression is associated with inflammation in the body.  The positive effects on depression may be due to the reduction of inflammatory cytokines which have mood enhancing effects [3]. There is also an increase in dopamine levels after cold exposure which play a big role in motivation and reward. When you feel satisfied after reaching a goal, it is due to a rush of dopamine.

  1. Stimulates weight loss.

Cold water immersion is associated with increased metabolism and the activation of thermogenesis.  We store two types of fat in our bodies.  White fat is stored when we consume too many calories and this is the unattractive and unhealthy fat that most of us want to get rid of.  We also have brown fat that generates heat by burning white fat. This is the stuff that we want active and the release of the neurotransmitter norepinephrine also stimulates brown fat cells into thermogenesis.  Studies saw an increase in free fatty acid levels and a reduction in glucose after cold water immersion [5].

  1. Speeds up muscle recovery and improves circulation.

Cold exposure is commonly used to relax sore muscles after training and most of us would know that this is due to the reduction in inflammation in your muscles due to reduced swelling and narrowing of blood vessels [2].

A little known fact is that cold plunges also restore vagal tone and normalize parasympathetic modulation of heart rate following intense exercise [6].  This is significant for recovery because it means that your heart goes back to operating normally faster than it would have without the cold plunge, this is referred to as a more efficient return to baseline neural activity of the heart [6].

This effect occurs because a cold plunge increases blood flow back to your heart and it also increases the amount of blood pumped out of your heart during the cold plunge. This effect was however only seen if a large portion of the body was exposed to cold water. It is brought about because of vasoconstriction which means the muscles in your extremities contract to narrow your blood vessels so that blood can flow to your vital organs to heat them up.  Cold water immersion also reduces the sensation of pain in muscles [1].

  1. Increase alertness and improves sleep.

Cold exposure definitely gives you the morning kick you need to start your day.  I feel energised after a cold shower or plunge which makes sense since the deep breathing during cold exposure will increase blood flow stimulation of the nervous system.  The energising effect is also due to the production of cortisol (your stress hormone) after cold exposure which wakes you up and kicks your circadian rhythm into gear.  If your cortisol levels are high in the morning and low at night, you can naturally relax later in the day as you get ready for bed. This is how cold water immersion improves your sleep.

It is therefore best to get your cold exposure during the morning and not at night.  I have recently made the mistake of taking a plunge before bed; I struggled to sleep after the kickJ. Now I know why.  It’s because the cold plunge increases your cortisol and norepinephrine levels for up to an hour after exposure [1].

  1. Shiny hair and smooth skin.

The main benefit of cold water for your skin and hair is that it closes pores and prevents the loss of natural oil.  Hot water can dry out your skin and hair, I often hear advice to wash your face in cool water and to avoid excessively hot water on your skin for this purpose.  Cold water immersion gets your skin looking smooth and healthy and your hair soft and shiny.

  1. Improves fertility in men.

It is a known fact that fishermen who stand waist deep in freezing water all day are very fertile.  If you think about the anatomy, the testes were designed to be cold, that is why they are outside the body cavity.  Cold water immersion increases sperm count by increasing testosterone levels.  If you are planning on procreating it might be a good idea to cool down often.

I love the fact that this type of shower is often referred to as the “James Bond” or “Scottish Shower”.  You can always play your favourite Bond theme song to mission into the icy water.



  1. Chris M Bleakley CM, Davison GW. What is the biochemical and physiological rationale for using cold-water immersion in sports recovery? A systematic review British Journal of Sports Medicine 2010;44:179-187.
  2. Gregson, W., Black, M.A., Jones, H., Milson, J., and Morton J. (2011). Influence of cold water immersion on limb and cutaneous blood flow at rest. American Journal of Sports Medicine, 39: 1316–1323.
  3. Jennifer C. Felger and Francis E. Lotrich, Inflammatory Cytokines in Depression: Neurobiological Mechanisms and Therapeutic Implications. Neuroscience. 2013 Aug 29; 246: 199–229.
  4. Shevchuk NA, Adapted cold shower as a potential treatment for depression. Med Hypotheses. 2008;70(5):995-1001.
  5. Smith DJ1, Deuster PA, Ryan CJ, Doubt TJ. (1990). Prolonged whole body immersion in cold water: hormonal and metabolic changes. Undersea Biomed Res. 1990 Mar;17(2):139-47.
  6. White and Wells: Cold-water immersion and other forms of cryotherapy: physiological changes potentially affecting recovery from high-intensity exercise. Extreme Physiology & Medicine 2013 2:26.