Diving into a long hole cut out of the ice on a river, Viktoria Tsuranova swims a few strokes and flashes a smile at the photographer capturing the moment for her Instagram account.

She is one of a new generation of Russian "Walruses" — young people taking the plunge into frozen lakes and rivers in search of health, natural highs and Instagram likes.

Once the preserve of old men in Speedos, ice swimming is now fashionable.

Devotees swear it wards off not just colds but cellulite — as well as giving them a rush of euphoria.

"A sporty way of life is right on trend now," says Nikolai, a member of Moscow's Walruses of the Capital ice swimming group, who is dressed in a grey onesie and drinking rosehip tea with honey.

He has just taken a dip in the L-shaped strip of water cut by the bank of the Moskva River, in the relatively balmy air temperature of -2 Celsius.

"There's a kind of new wave of young people coming up now, following the generation that set the standard for walrus swimming — the older generation."

Tsuranova, a fitness blogger, later posts a video and photo of her swim on Instagram, where she has 103,000 followers.

Shivering a little in a fur coat after her swim, she said: "I'm just interested in the extreme, in testing myself. I'm scared every time."

She added she hasn't been ill once over the winter and said it's "a great way to prevent excess fat deposits and cellulite".

Russia's winter swimming federation, based in the Siberian city of Tyumen, lists joint health and good skin among the benefits.

But it also warns that those with weak hearts or breathing problems should not attempt it.

Depending on their experience, ice swimmers tend to stay in the water for anything from one to around five minutes.

A separate study by Tyumen scientists in 2015 found that the cold temperature caused stress on the body for people who regularly swam in ice for a period longer than ten years.

While also practised in Scandinavia and China, the sport is particularly popular in Russia, where cold water is seen as a way to toughen people up.

The club's star swimmer Osman Delibash, 26, who recently made a video showing herself sitting for an hour in the frozen pond in her garden, was in the process setting a record recognised by a Russian association for the longest stint in cold water by a woman.

She has also won a string of medals for swimming distances of up to a kilometre in sub-zero air temperatures, trains soldiers serving in extra-cold environments, and performs as a stunt woman.