Do you finding swimming in a pool too restrictive? Then why not get out in the open water?
British stars Keri-Anne Payne and Cassie Patten did just that in the 2008 Beijing Olympics, claiming silver and bronze medals respectively in the event's inaugural 10 kilometre marathon.
The duo's success has convinced plenty of people to delve into the lakes, with 4,000 swim fans partaking in this year's Great London Swim at the Royal Victoria Dock, near Canary Wharf.
"Open water swimming is great because it is free," Patten, who retired from swimming last year, told Get Involved. "You have no chemicals in the water, you're not constrained by walls. It's about getting in there and being at one with nature.
"That sounds silly but that's what I love about it. You have a lot of tactics that go on under the water in competition - feet pulling, goggle ripping - but for social swimmers it is a lovely chance to get out there."
Payne added: "I was always going to be a swimmer. It has taught me how to be disciplined and how to enjoy things. Swimming is such an important life skill.
"I think that it is vital that children learn to swim at a young age and getting families involved is the biggest thing. If mum and dad go swimming then their little kids will want to go swimming as well."
Open water swimming is growing in popularity up and down the country, including at Serpentine Swimming Club in London's Hyde Park and at a lake in Shepperton, Surrey, where 500 people swim a week.
Speaking at the recent Swim Round the Pier festival in Brighton, Swim Trek founder Simon Murie says people must take a few precautions before they decide to take the plunge.
"Never swim alone," he said. "Make sure someone is on a boat near you or at least on the shore looking after you. Plus, a nice thick, brightly-coloured hat keeps you warm and ensures boat traffic can see you."
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