WW ’s Dr Melanie explains why open-water swimming is good for us

Like any exercise, swimming can help to prevent circulatory disease, cancer, diabetes, obesity, and other conditions.

Being outdoors, especially in green spaces, can boost our mood and help with mental health problems. Going for open water gives an added fun factor.

It’s physically and mentally less predictable than lane swimming, so it challenges our brains as well as our bodies.

Swimming with other people builds social relationships, which is also very good for our health.

Extra ultraviolet light on our skin produces bonestrengthening vitamin D, even on cloudy days (but remember to wear waterproof sunblock if you’re outside for long periods).

What to look out for

Never swim alone, too far, or after a heavy meal, and wear a brightly coloured hat and swimsuit/ wetsuit so you’re easy to see.

Plunging into cold water, even on a hot day, can trigger dangerous muscle cramp or even, rarely, heart problems. Ease in slowly, and get out when you feel tired or cold, and have warm clothes waiting.

Be sure to look out for warning signs, beach flags, and the location of any life-rings and emergency telephones.

Also check for hidden hazards: submerged objects, depth changes, currents, tides, toxins (sewage, blue-green algae, Weil’s disease from rat urine).