When can I start swimming and training outside?

Spring has arrived. The open water is warming up. We’re optimistic about being able to do some outdoor swimming events or challenges this summer. So when can you get in the open water and start swimming again?

It’s an interesting question. For those who have swum outside through the winter, it’s mystifying. As far as they are concerned, the water is already warm, and they never stopped swimming outside anyway.

However, if you want to do some serious, head-down, longer-distance freestyle, then it’s a legitimate thing to ask. Outdoor winter swimming, for most people who do it, is about having fun, not fitness. You simply can’t stay in the water long enough. Winter swimmers often swim head-up breaststroke and mostly don’t wear wetsuits.

With pools closed or operating with restricted opening hours, we expect to see more triathletes and competitive open water swimmers than in previous years wanting to get outside for training swims. We can’t give you a precise answer to when you can start swimming outside again as everyone is different, but we can suggest some things to take into consideration.

What do you want to get into the water for? If you just want to experience being back in the open water and don’t mind if it’s only for a few minutes, then start as soon as you like, but please ensure you read up on cold water shock and winter swimming advice first. If you want to swim longer, and like to be comfortable, then you may have to wait until it’s a little warmer.

If you’re a triathlete, it’s worth bearing in mind that swims may go ahead with temperatures as low as 11 degrees – and it pays to be prepared for this. Many years ago, I did a sprint distance triathlon in May, in unseasonably cold weather. It was my first outdoor swim of the year and I had never swum at 11 degrees before. I now know you can acclimatise to low temperatures and I find 11 degrees tolerable, even pleasant, for short swims, but at the time it was a horrible experience.

Therefore, if you have an early season triathlon or open water swim, try to get in the water beforehand, even if you’re just dipping in for 5 to 10 minutes. Ideally, do five or six swims in the few weeks leading up to the event as that is enough to significantly reduce the impact of cold water shock.

For longer training swims, you need to find your own comfort and tolerance levels, and there is a wide variation between people for what that means. At 16 degrees, for example, some swimmers can be at thermal equilibrium without a wetsuit and swim indefinitely while others are plunging towards hypothermia in less than 30 minutes. The biggest factors are body size and shape, with acclimatisation playing a smaller role.

The most difficult thing for many people coming back into the open water in spring, especially when wearing a wetsuit, is often discomfort or pain in the hands, feet and head. For me, once the water is above about 12 degrees, I find this pain recedes after a few minutes, but other people experience it differently. Gloves or booties will help, but they make swimming more difficult. A neoprene hat makes a huge difference and I recommend using one early in the season. Remember, you can also add layers underneath your wetsuit for extra warmth.

One useful tip is to separate getting used to open water from improving your fitness. Make acclimatisation rather than training your objective for those first few swims of the season. Don’t worry about distance, just dip. Another thing you can do is to get in the water for 10 minutes, get out and warm up again, and then do another 10 minutes. You should find your second swim a lot more comfortable than the first. If you’ve got access to a heated pool, continue your fitness training there. Alternatively, do your swimming training with stretch cords as a temporary measure.

The key thing, as ever with swimming, is to stay safe. Make sure you understand the increased risks of swimming in cooler conditions. The second thing, enjoy yourself. If you really find swimming in the cold unpleasant, and you don’t have an event you ought to acclimatise for, why bother? Wait until it’s warm and swim in comfort.

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I created Outdoor Swimmer in 2011 (initially as H2Open Magazine) as an outlet for my passion for swimming outdoors. I've been a swimmer and outdoor swimmer for as long as I remember. Swimming has made a huge difference to my life and I want to share its joys and benefits with as many people as possible. I am also the author of Swim Wild & Free: A Practical Guide to Swimming Outdoors 365 a Year and I provide one-to-one support to swimmers through Swim Mentoring.