On Tuesday morning, 37-year-old Sarah Thomas from Colorado, US, became the first person to swim the Channel four times without stopping. In just over 54 hours of swimming, and 130 miles, she redefined what an endurance athlete could be for a generation: until this week, only four swimmers had ever managed to make the journey three times without stopping.At an age when most of us are thinking about how little exercise we can get away with, and only a year after going into remission from breast cancer, she completed the feat with minimal fuss, emerging to a treat of champagne and M&M’s, with the comment, “I’m pretty tired right now.” Rather more tartly, her mother called her “a freak of nature”.

But those of us who follow outdoor swimming will understand that it isn’t actually that surprising that it was a woman who accomplished something so dramatic. Because women have been quietly dominating outdoor endurance swimming for some time now. A combination of obvious and not-so obvious factors currently means that across average times of male and female Channel crossings, the average female time is faster than men’s.

In general, women have a greater distribution of slow-twitch muscle fibres, which – while less useful for explosive sprints – mean the body is more resistant to fatigue, and better at coping with feats of endurance. Women also have a higher distribution of fat in their lower body than men, resulting in better buoyancy in the water. This is of particular importance on a competitive swim across the Channel, where wetsuits are not permitted. Swimming is also a sport where technique is everything: it doesn’t matter how much you can bench press or how fast you can run if you can’t glide through the water with minimal effort.

And then there’s mental resilience, something that sports scientists are increasingly seeing women excel at in endurance events (anything over six hours). Thomas dedicated her swim to fellow cancer survivors, something that will surely have stilled her mind in moments of doubt. Her support team also referred to her swimming as having been a means of coping with treatment last year.

Facebook Twitter Pinterest ‘In Channel 4’s Sink or Swim, a ramshackle group of reality stars trained for an attempt to swim the Channel in aid of Stand Up to Cancer.’ Photograph: Channel 4

Jenny Landreth, author of Swell, a “waterbiography” that tells her own swimming story alongside those of swimmers such as Gertrude Ederle, the first woman to swim the Channel, describes how those following Thomas on her swim became “a big cheering, emotional community in the end. It was a great big four-act drama with excitement and jeopardy and suspense and then a fantastically happy ending – and the most brilliant hero at the centre of it. There’ll be a lot of women, of all abilities, who will channel her (ho ho) when we next get in the water, even though we know we could never do what she did.”

She certainly isn’t alone in being a woman who has sought solace in the water. In recent years there has been a rash of swimming memoirs (my own included) in which women navigate issues such as grief, alcoholism, infertility and heartbreak by plunging themselves into icy seas and lakes. There is an undeniable thrill to feeling the sting of cold water alert you to the fact that regardless of your pain, you are still alive and would quite like to stay that way. The necessary engagement with nature that outdoor swimming brings is an always-welcome balm to the soul. So it was particularly thrilling to follow one of our own as Thomas’s support boat tracked its steady course back and forth across the Channel, day after day.

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Some have criticised the recent flurry of nature writing – including swimming titles – as being little more than “white people go outside” books. But Channel 4’s Sink or Swim series was significantly more diverse. A ramshackle group of reality stars trained for an attempt to swim the Channel in aid of Stand Up to Cancer. It featured Olympian Linford Christie and Coronation Street star Sair Khan talking about how black men and Muslims are often stereotyped as non-swimmers. The Last Leg star Alex Brooker, who was born with arm and hand deformities, and had a leg amputated as a baby, was also part of the team. Expectations were defied, tears were shed, and to almost everyone’s amazement, miles were swum.

At a time when turning on the TV or glancing at your phone carries the significant risk of catching sight of the worst in human nature, it was a joy to see swimming provide two such positive narratives in one week. We can be great, even if we have to do it off dry land.

• Alexandra Heminsley is the author of Leap In and Running Like a Girl