I’ve swum in lakes in Switzerland in the rain, in small lochs in Scotland, in pools and lidos, outdoors and indoors, heated and unheated. I’ve swum from Europe to Asia, in fjords in Norway and rivers in England and in very icy sea in the arctic circle in winter. I’ve swum in posh hotel rooftop infinity pools, in scummy council pools and I’ve swum from England to France. Anywhere. Everywhere. Always. Swimming is who I am.

Sometimes, when I push off underwater from the wall in a pool, with my arms outstretched in front of me, hands clasped tightly one on top of the other, I tilt my head slightly further up than usual and look in front of me. The force of the push-off sends water rushing along the muscles making them ripple as the water passes up my arms. On the index finger of my right hand a little bubble forms temporarily on my fingernail, lingering there until I break the stretched out form and pull my right arm down and into my first stroke. I am suspended in time for what seems like forever. It completely mesmerises me, this ritual. And it lasts about two seconds. Swimming can be completely hypnotic.

Let’s not over romanticise it. It can also be a misery. There are plenty of days when I set my alarm to go swimming early and just hit the alarm clock and roll back over, groaning. There are just as many when I plan to go swimming after work and am just too dog tired to contemplate it – when a night curled up on the sofa with a cup of tea seems infinitely more sensible than stripping off and plunging into water. Then there are days when I go swimming and ache for half an hour until my body has warmed up, and I just feel like going home feeling dejected. I never get out at this point. There are days when some random aggressive swimmer in a crowded overheated pool decides to cut me up in the lane and I feel stressed and intimidated. There are days when I have to force myself to stay in and swim because it’s been boring and I haven’t felt right.

But there is not one day when I’ve regretted going swimming. Social swims with mates who love the same things as you, swims in clubs where you are pushed to swim faster and harder, challenging swims in murky waters across straits and channels with jellyfish and other wildlife. Long, cold miserable swims in interminably long lakes. Slow contemplative swims in tiny glorious hotel pools in hot countries with water twinkling in the sun. Swims in picturesque ponds with ducks and moorhens for company and low hanging willow trees. They all have their own qualities. They all have rewards.

A few weeks ago I was swimming at London Fields lido with Mari, an old swimming club buddy who was in London visiting for the weekend. We had arranged to meet up but would never dream of an encounter that didn’t involve swimming. We met in the pool, did a few lengths to warm up, and then a session involving intervals of fast lengths with rests between them, then 10 seconds' rest counted out silently on Mari’s fingers held high.

We had just finished our session when a fellow swimmer leaned over and asked: "What are you training for?" We looked at each other bemused. We weren’t training for anything really. Mari said "training for life" and I said "training for sanity" but in reality we both knew the truth. We were training for coffee and a large cheese toastie to share in a trendy Dalston cafe near by. Not that we couldn’t have cut the swim and gone straight for the coffee and toastie. Of course we could. But how would that work? In truth I have no idea. Every coffee, every cake, every toastie, every conversation I’ve had with Mari has been preceded by a good swim. Why would you not swim? You feel so much more alive. You feel so tingly, so uplifted, so clean, so happy, so energised, so at peace.

The swims that I love the most though are probably the swims on my own. My favourite place to swim in London, where I live very centrally, is Parliament Hill lido. It’s a giant stainless steel tank that twinkles in the sun like a jewel. Unheated, it can often be uninviting to those who prefer warmer water. It’s often empty. In the spring and the autumn when the water is a reasonable temperature but the air is cold, and sometimes it’s gloomy and raining, I slip into the water, and am there marvelling in the feeling of space and solitude. I feel the water surround and envelop me. I swim up and down and often I just think of nothing more than counting my strokes between each breathe. “One two three four – breathe – one two three four – breathe – one two three four – breathe.”

Whole lengths and even hours can drift by with the same chant. Listening to the sound that my arms make when hitting the water, to the noise of the bubbles as I breathe out under water; watching my arms stretch out in front of me, pale and wan in the diffused underwater light; feeling my body move through the water; watching other swimmers’ legs kick and flutter or dangle from the water’s surface as I pass by; looking at the sky above. Even though there may be others around me I am alone in this space, lost and in a blissful solitude of near sensory deprivation. But at the same time I feel cocooned and enveloped. It’s a feeling that you cannot get any other place that I know.

I love swimming because I feel at peace in the water. It makes me feel younger, more alive, more relaxed, more at ease than almost anywhere else. It sets the world in slow motion and allows me time to catch up.

Interested in finding out more about how you can live better? Take a look at this month's Live Better challenge here.

The Live Better Challenge is funded by Unilever; its focus is sustainable living. All content is editorially independent except for pieces labelled advertisement feature. Find out more here.