The Joy of Cold Water Swimming


Why would anyone want to swim in cold water? Coralie Frost clues us in on the positives of this popular activity.

I grew up by the seaside in Felixstowe. I always had the sea on my doorstep and while my childhood was mostly playing in the waves, rather than bracing myself for a cold water swim, it has always been part of my life.

To enjoy cold water swimming it’s best to start in the summer when it’s warm to acclimatise, rather than dive straight in during the colder temperatures. In the chillier months the first thing that happens when you get into water is cold shock response (rapid breathing, increased heart rate and blood pressure). The best tip is to relax, breathe slowly and immerse yourself gradually and calmly. After awhile you get used to the cold water and the cold shock will get easier to manage.

So why should you start swimming outdoors? Here’s a couple of reasons to get started.

The author after an exhilarating dip in the North Sea.

1. Open water swimming is good for the body and mind

We all know that regular exercise is good for the body and mind. However, cold water swimming has been shown to help with mental health conditions such as depression, anxiety and stress. It has been reported that immersion in cold water evokes a stress response: a set of physiological and hormonal reactions that evolved millions of years ago to cope with a wide range of threats.

I normally swim in the morning, around 7 am, just before work at Serpentine Lake. I’ve found I’m more alert throughout the day. I always find that the colder the water the better my skin feels. And who doesn’t want that post-cold swim smug glow at their desk?

The beach at Felixstowe.

2. Battle the common cold

Ask anyone who regularly cold water swims when their last cold was, and I bet you they haven’t had one in a while. Yes, it is surprising but the immune system gets a boost from the cold water.

Recent research shows that regular cold water immersion can boost your body’s levels of antioxidant glutathione. All of this can boost your immune system and reduce risks of diseases too.

The London Docks.

3. You don’t have to swim long, all the time

When it’s really cold you don’t have to swim for long to get the benefits. In fact, most people during winter won’t swim for more than a couple of minutes. The water isn’t a place for heroes and just because you swam for a mile one week, doesn’t mean you will be able to stay in the water as long the next week while temperatures continue to drop.

Bitter temperatures mean that cold water swimmers can often get brain freeze and icy, tingling limbs. You have to know your limits and be safe otherwise you could be at risk of hypothermia. Therefore, just having a couple of minutes in the water can still give you the benefits, boost and adrenaline rush.

The Serpentine Lido.

4. It’s sometimes free!

In London there are plenty of places to swim open water, often for a small price:

  • The Serpentine Lido is open 365 days a year, between 5-9.30 am, if you are a member of SSC at a price of £20 per year.
  • London Docks is open most of the year, and operates by pay per visit. It’s a great venue and feels quite busy with planes going overhead to City Airport.
  • Shepperton Lake is open from May-September and while it’s a little bit outside London, it’s beautiful to visit.

However, just a short train journey can take you to the coast where the sea is free! My favourite spot is my hometown in Felixstowe, Suffolk. The North Sea is salty and very different to the flat lakes in London.

To start you will need: a swimming costume, goggles and lots of warm clothes for afterwards. It’s also best to bring a flask of tea or a hot drink to re-warm your core. Some people also wear a wetsuit in the water and neoprene gloves, hats and booties. You don’t need to go in the water in ‘skins’, and no one will judge you if you don’t. Do what’s best for you so you get the most enjoyment out of swimming.

The Outdoor Swimming Society is an incredible resource for swimmers. They’ve included guidelines on how to approach cold water swimming safely:

  • Approach it with the same caution you would exercise – start slow and warm.
  • Make sure you can swim and go with a friend who can swim.
  • Start in summer/early autumn when UK sea temperatures are 15-20°C.
  • Start shallow – a gently shelving beach, or somewhere with a ladder.
  • Go on a calm day – the initial two to three-minute gasp during which you can inhale water is the risky part. Relax, do as little as possible and keep your head above the water for this period.
  • Time yourself for two to three minutes. Once your skin reaches the same temperature as the water you’ll feel warm.
  • Six three-minute swims will have an effect on your cold shock response that will last for months. As for your mood – you’ll have to be the judge until there are more studies.

Coralie Frost started running in 2014 and has since fallen in love with marathons and triathlon. She’s one of Serpentine’s Mental Health Champions, supporting any club members who are experiencing mental health problems.