Updated: Dec 6, 2022
Doesn't it feel good to be heading out for a dip when so many outdoor swimmers are packing away their kit for the winter? On World Mental Health Day, here's why dipping is winter's silver lining making us feel excellent in the darkest of times.
The BEST thing about winter
Don't get me wrong, I love Christmas. Food, presents, family, childhood comforts, films in front of a log fire. But the trouble with Christmas is that it's exhausting. Like most highs, it comes with a hangover: financially, gastronomically as well as the groggy kind.
Winter swimming, on the other hand, is a high like no other. You start to get the buzz around the end of October as the water temperature dips below 12C, and when it gets below 5C, the post-swim glow can keep you going for days.
How to acclimatise
If you're the sort of person who starts Christmas shopping in the January sales, you'll understand the concept of preparation being key. Ok, you can leave your Christmas shopping until December 23rd without it being a huge disaster (honestly, I know!), but you can't really start winter swimming in the depths of winter. Why not? Because it takes your body a while to acclimatise.
Acclimatisation is a word that you've probably heard in relation to swimming outdoors at any time: here's an excellent article by Dr Heather Massey that describes the process. Used in relation to getting into cold water for the first time, acclimatisation describes everything from the initial cold water shock response to feeling at ease and swimming to how you recover afterwards. But what does it actually mean in relation to winter swimming?
In winter swimming, acclimatisation is a process that takes months or even years. It is a very gradual change in your response to being immersed in cold water, where your physical reaction to a cold dip gets better over time and your tolerance increases. For example, in my first year of winter swimming, I got unbearable pain in my fingers at 6C. Last year, my third winter, I didn't feel that pain until 2C.
The research that Heather Massey has been doing at Portsmouth's Extreme Environments Laboratory shows that swimmers can habituate the cold water shock response very quickly. That initial gasping response when you immerse your body (not head) in cold water actually halves after as few as five or six three-minute immersions. This reduced response lasts a while so that if you're ill or go on holiday and miss your cold water dips, you don’t start all over again. In fact, half of this cold water shock reduction will be present 14 months later.
The key is to start dipping before it gets really cold. Ideally, your outdoor swimming habit should begin in the summer when the water's warmer than 16C. But now, in autumn, is your last chance to catch the winter swimming train before it gets away. And then you carry on, once, ideally more times, a week as the temperature drops. Keep those dips really brief -- there is no advantage had from staying in for a long time. In fact, the main wellbeing benefits happen in the first two minutes, after that, you're just paddling closer and closer to hypothermia.
So, do the benefits decrease as you get used?
It appears that the benefits are cumulative too. Your ability to handle stress, your propensity for anxiety, depression or other mental health issues, and your immune system all improve over years rather than weeks. In other words, don't leap in and expect to be able to give up the meds or skip your flu jab; like all good things, it takes time.
That said, if you do suffer from your mental or physical health, winter swimming is very likely to help from the start. It does improve your immune system, it does help you better tolerate stress and that improves conditions like anxiety and depression.
Tingle all the way
I've suffered from Seasonal Affective Disorder for the best part of thirty years. It's not completely understood, but it's thought that less time in the sun during the shorter autumn and winter days stops a part of your brain called the hypothalamus from working properly. That increases the hormone melatonin that makes you feel sleepy; reduces serotonin which makes you feel low or depressed, and messes with your body's internal clock as it uses sunlight to time various important functions, such as when you wake up.
But winter swimming means that I no longer hate the winter. It gets me outdoors, the cold water boosts my serotonin levels and it certainly makes me feel awake. And the best bit is that there's no hangover of any kind.
So, while most people look forward to Christmas as the sparkle in the midwinter gloom, winter swimmers look forward to the bite of the cold water, the tingly skin and post-swim rosy glow. And for many of us, it's a total game-changer.