Sharon is a regular swimmer with HOWSC and knows a thing or two about health related matters. The following article supports our hypothesis that there's method in our madness!
The Health benefits of cold-water swimming
All of us who engage in swimming in rivers, lakes and the sea in temperatures below 100 C (sometimes significantly below!) will attest to its benefits. There are many claims that it is good for our health and wellbeing. I thought I would try and discover what the scientific evidence is in support of the anecdotal claims made by a bunch of lovely people shivering and huddling round their steaming mugs on cold and frosty mornings.
I have identified five aspects of life about which there are claims that cold water swimming enhances:
There have been a number of studies published that have provided information about the link between cold water and a reduction in the stress and inflammatory responses. All of the five areas above are probably impacted by these reduced responses.
Immersion in cold water elicits a physiological stress response that is aimed at protection and survival. This response is significant even in water up to 200C but becomes more pronounced the lower the temperature.
Humans have evolved only one general reaction to stress, so this is the same response whether you are being chased by a bear or stuck on an overcrowded train.
The stress reaction results in increased heart rate, blood pressure, breathing and the release of stress hormones. All very helpful if you need to run away from a bear but if simply stuck on a train just make you feel wound up and is, in physiological terms, an over reaction. This over reaction puts strain on the heart and reduces feelings of wellbeing. There are many aspects of modern life that can produce this reaction in us but because they rarely require us to run away or physically fight they can be harmful over time.
Current studies at the Extreme Environments Unit at Portsmouth University have shown that repeated immersion in cold water (apparently as few as four) results in a reduced stress reaction so that when we get in the water our heart rate and blood pressure don’t go up as much and we are able to control our breathing. In other words our bodies learn not to over react. If this reduced reaction is replicated in response to other causes of stress in our lives (cross adaption) it could have wide ranging benefits particularly in relation to circulatory and mental health. Research is being undertaken currently at Brighton and Sussex University Hospitals into cross adaption.
Another aspect of the stress response is inflammation. This is an extremely complex physiological response, which again, evolved to protect us but if it occurs to excess or inappropriately can be disadvantageous.
High levels of inflammation have been linked to a variety of disorders including depression, cancer, inflammatory bowel disease and arthritis whilst low levels have been linked to long life. Work at Brighton is on-going, examining how the inflammatory response may be reduced by cold water adaption. Early results show major benefits in relation to depression for which there is increasing evidence of a link with inflammation. This was shown in a BBC One programme earlier this year “The Doctor Who Gave Up Drugs” about a young woman who was able to come off anti-depressants completely by regularly swimming in a local lake.
Part of the inflammatory process and the stress response to cold water immersion is the activation of white blood cells. White blood cells are like battalions of soldiers mobilised when the body faces stress, when this is an invasion by a bacteria or virus the white cells aim to overcome this foe and prevent infection. Whilst there is (mostly anecdotal) evidence that cold-water swimmers have a lower incidence and severity of colds during the winter, further work is required but it may be that we are better at mobilising our white blood cells.
Any form of exercise cause the brain to produce Endorphins, again part of the stress response. Endorphins are our own personal narcotics or “feel good” chemicals they reduce pain and increase the “feel good factor”. Cold- water swimming seems to have a more pronounced effect on endorphin release than other sports as it quickly brings us close to the pain barrier.
All of the above responses require the body to expend energy, this combined with the energy required to warm up afterwards, explains the increase in calorie burning. There are claims that cold-water swimmers tend to be thin. Without wishing to cause offence there is only moderate evidence in support of this amongst HOWSC swimmers however this is may be related to enthusiastic post swim breakfasting and cake eating activities.
In summary there is quite a lot or research done into this area some of it dating back to the 1980’s but at present the evidence base is not very strong for most of the claimed benefits. That said there is work going on currently as mentioned above and there is increasing evidence that reduction in the body’s stress and inflammatory responses occur due to cold-water swimming and this may explain 1-4 above although number 4 is often cancelled out by other factors!
[Editor: And what about number 5? It's what we've all been waiting for!]
There is limited evidence that I could find in support of cold-water swimming increasing libido. However if we are all healthier generally in mind and body this may naturally follow? Perhaps we should conduct an anonymous straw poll of HOWSC swimmers?
Any discussion of the health benefits of cold-water swimming must carry the caveat that there are also risks of which we should all be aware, but this is perhaps the subject of a future article?
Of course we all know that despite the science, gathering regularly with a bunch of like-minded people in beautiful surroundings is beneficial and we are all healthier and well rounded as a result!
Here’s to a Happy and Healthy Swimmy 2018 for us all!!
Although this wasn’t intended as a piece of academic writing if anyone is interested in further reading please see the list below of some of the papers I looked at:
Brenner I. K. M Castellani J.W. Gabaree . Young A.J Zamecnik J. Shephard R.J Shek P.N 1999 “Immune changes in humans during cold exposure: effects of prior heating and exercise” Journal of Applied Physiology Vol 87 (2) Pages 699-710.
Collier N. Massey H.C Mitch Lomax M. Harper M. Tipton M. (2015) “Cold water swimming and upper respiratory tract infections” Extreme Physiology & Medicine Vol 4(Suppl 1):A36
Dugue B. Leppanen E 2000 “Adaptation related to cytokines in man: effects of regular swimming in ice-cold water” Clinical Physiology and Functional Imaging Volume 20 (2) Pages 114–121.
Gleeson M. Bishop N.C Stensel D.J Lindley M. R Mastana S.S Nimmo M.A (2011) “The anti-inflammatory effects of exercise: mechanisms and implications for the prevention and treatment of disease” Nature Reviews Immunology Vol 11 Pages 607-615
Golden C. Tipton M. J. (1987) “Human Adaptation to Repeated Cold Immersions” Journal of Physiology Vol 396, Pages. 349-363
Huttunen P. Kokko L. Ylijukuri V. (2004) “Winter swimming improves general well-being” International Journal of Circumpolar Health Vol 63:2 Pages 140-144
Soledad Cepeda M. Stang R. Makadia R (2016) “Depression is associated with high levels of C- Reactive protein and Low levels of Fractional Exhaled Nitric Oxide: Results from the 2007-2012 National Health and Nutrition Examination Surveys” Journal of Clinical Psychiatry 1666-71
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