Inspired by Floating, Joe Minihane’s memoir about swimming in seas, rivers and lidos around the UK, I plan to do more outdoor swimming this year. I have ample opportunity here in New Zealand, being lucky enough to live in a house with a pool in the garden and ten minutes walk from the sea. I already swim most days during the hot summer months but intend to try extending the season.
Swimming, especially in cold water and sea water, seems to confer mental and physical health benefits over and above those to be gained from exercise in general. Mechanisms for this include the physiological stimulation of being in cold water, the meditative state induced by rhythmic movement and deep breathing, being surrounded by nature, and absorption of the minerals present in the sea. Many people feel an immediate uplift of mood and energy when they go for a swim. Regular swimming over a period of several months appears to reduce stress, helps to regulate the immune and endocrine systems, and reduces inflammation. Regular swimmers catch fewer colds, and there is preliminary evidence that swimming can help in the management of numerous medical disorders including anxiety and depression, eczema and psoriasis, hypertension and diabetes. However it takes time for the body to adapt to the demands of cold water swimming and reap these health benefits. So it is important to build up the practice gradually, and to be aware of the potential hazards as outlined below.
The shock of getting into cold water can throw all body systems out of balance, causing the sudden onset of breathing difficulties, muscle spasms, raised blood pressure and disordered heart rhythm. Cold water shock can be fatal. Hypothermia can ensue after more prolonged immersion and is manifest by shaking, weakness and confusion. To avoid hypothermia it is important to wrap up and warm up after the swim. Individual tolerance to cold varies but my understanding from various websites is that water temperatures below 15C are always dangerous, and that beginners should probably not start below 20C. Wild swimming in rivers or seas carries the risks of infections, injuries, and drownings due to powerful currents or tides.
Being a person who gets cold easily I considered buying a wetsuit, but after a trial fitting decided against it. I found the suit so cumbersome to take on and off, and so constricting to wear, that I felt it would detract from the pleasure and benefit of swimming. Perhaps a wetsuit jacket would be a better alternative and enable me to stay in the water for longer. But I am going to wait till the weather gets better before I start my regime, and however much I manage to improve my resilience I cannot see myself ever joining the hardy souls who take part in the midwinter swim in our local harbour.