Dipping and swimming in cold water is increasingly being touted as good for health. But what does the science say?

By Elaine K Howley

This is how cold water makes you feel!

Image: Ian Wood

ELAINE K HOWLEY

For roughly seven years, the young woman named Sarah who was described in a 2018 case study published in the British Medical Journal had struggled with major depressive disorder. She was diagnosed at age 17 – though she’d been experiencing symptoms long before that – and by the time she was 24, she had tried various different anti-depressant drugs. These largely failed to control her condition and left her with unwanted side effects.

At age 24, Sarah gave birth to a daughter and decided she wanted to live both depression-and medicationfree. This would be a tall order, but not insurmountable, as the case study describes, because Sarah had access to a secret weapon many of us swimmers already know about: cold water.

Under the guidance and observation of a team of cold-water researchers at the University of Portsmouth, Sarah began undertaking weekly swims in open water in April, and immediately noticed an improvement in her mood after each swim. That boost in spirit lingered long after Sarah had warmed up.

Over the course of the six-month study period, Sarah continued her once- weekly sea swims, increasing her time in the water to about half an hour by the conclusion of the study in September.

Though this is just one person’s experience, the result offers some compelling evidence that cold water has the power to cure what ails you; in Sarah’s case, within four months of beginning a cold-water swimming regimen, she no longer needed any medication to control her depression.

IS COLD WATER THE KEY TO GOOD HEALTH?

Sarah’s story – like those of so many other people who’ve stumbled into open water swimming as a means of managing stress, improving their mood, or just for fun – illustrates that there could be several potential medical applications for cold water therapy. While the most prominent and so-far best explored area relates to mental health conditions such as depression and anxiety, researchers have been investigating how other aspects of health may improve with cold water swimming including: