FEATURES,  View from the Water

The importance of being acclimatised

‘To lose one swimmer may be regarded as a misfortune; to lose 30 looks like carelessness.’ Ok, so they weren’t lost, but they certainly weren’t there. And when I started swimming I definitely wasn’t on my own.

Last night was the first open water training session of the season from Swim For Tri at the Serpentine Lake in Hyde Park. Venue of the 2012 Olympic open water marathon and home of the Serpentine Swimming Club, the Serpentine is an iconic swimming spot and an outdoor swimming oasis slap bang in the middle of central London. Swimming there on a summer evening as the sun sets below the bridge is a swimming highlight of my year. But where was everyone?

The session started out busy – two groups of swimmers divided into ‘skills’ and ‘fitness’. All, apart from one swimmer, were wearing wetsuits (me included). The water was 11 degrees Celsius. After our warm-up the first set was 4x200m practising sighting – and it was necessary, as the melee of swimmers made swimming in a straight line difficult. But by the end of the 2km main set I was pretty much the only person left in the water (and it wasn’t because I was the slowest swimmer in the group).

“Where is everyone?” I asked.

“They got too cold,” replied the coach.

Last month the RNLI warned against swimmers entering the water on the hottest day of the year so far without wearing a wetsuit. Cue much scoffing from hardened outdoor swimmers around the country. But the swimmers who got out of last night’s session weren’t all inexperienced swimmers: they included seasoned open water swimmers and triathletes. The difference being, of course, that they weren’t experienced cold water swimmers. For me, although I wouldn’t have wanted to swim the session skins, I have enough cold water experience for 11 degrees to be on the warm side. And that acclimatisation and experience (mental and physical) meant that I could comfortably complete the session.

So, even in neoprene, be aware that cool water needs acclimatising to if you are not used to it. Last night’s swimmers sensibly got out when they felt uncomfortable. Next week, as the water gets warmer and they become more acclimatised, they will be able to stay in for longer. If you are venturing into the open water for the first time this month, be aware that the water is still cool (especially for this time of year) and swim accordingly – don’t go beyond the limits of what you feel comfortable with. Enter the water slowly; splash your face with water to get used to the temperature and let a little water into your wetsuit. Last night many swimmers complained of ‘ice cream brain freeze’ – make sure you are wearing a thick silicone hat, or two. When wearing a wetsuit, it is the extremities that get cold first – consider wearing bootees or gloves. And if the cold is starting to make you feel a bit dizzy, it is probably time to get out.

Back in the changing room I asked my clubmate Martin if he had finished the main set. “Yes,” he mumbled, “but I can’t speak properly because my mouth is numb with cold.” What better excuse to indulge in the traditional accompaniment to cold water swimming: hot tea and cake. 

Stay up to date with The Dip, our free weekly outdoor swimming newsletter.

Jonathan is a year-round skins swimmer with a particular love of very cold water. He has competed in ice swimming competitions around the world. He is a qualified open water coach with a particular love of introducing new swimmers to the open water.