Cold water swimming may seem like an odd pastime to the uninitiated. But while you might question the sanity of those who decide to take an open-water dip in the depths of winter, research has shown there are actually a host of health benefits – both mental and physical – to taking the plunge.
The joys of such a pursuit are well noted – both anecdotally and scientifically – but there are of course risks.
Here, we reveal the reasons why you should dip your toes (and more!) into cold water this winter, and explain how to do so safely:
Cold water swimming benefits
Speak with any open-water swimmer, and they will likely wax lyrical about the joys of immersing yourself in cold, open water, often in wild locations such as lakes or rivers. But even swimming in cold water in a pool, such as a lido during the winter or early spring, will see you reap the benefits.
Nike Swim’s Jane McCormick is a World Record English Channel two-way crossing relay team member, as well as a Swim England Level 2 coach at Open Swim UK. Here, she reveals five main benefits cold-water swimming will bring:
‘When you swim outdoors, your body has to work hard simply to stay warm,’ explains McCormick. ‘Consequently, you burn more calories. The colder the water, the harder your body works to convert fat to energy. When this is coupled with your swim workout, the calorie burn can be increased significantly.’
‘When we jump into cold water, the extreme change in temperature signals to our heart to pump more blood to our organs,’ says McCormick. ‘As a result, circulation is improved, and toxins are more readily flushed out of our system, which leads to clearer skin and a healthy glow.’
Reduction of stress and enhanced mood
‘It’s widely known that any exercise helps increase the production of your brain’s feel-good neurotransmitters, called endorphins, which improve our mood and help to tackle stress and anxiety,’ says McCormick.
‘The rhythmic motion of swimming can help any stressful feelings dissipate, as you focus on your body’s movement,’ she adds. ‘It is almost an exercise in mindful meditation, as you glide through the water. Furthermore, when you immerse yourself in cold water, you feel a stinging sensation on your skin, which your body combats by producing yet more endorphins, which produce a feeling of elation once you get out.’
‘If you take to the open water regularly, you will find that your sleep is improved,’ reveals McCormick. ‘This is because cold water stimulates the parasympathetic nervous system, which helps your body rest and repair itself. This promotes a feeling of relaxation and calm, which should then result in a better night’s sleep.’
Boosted immune system
‘On regularly immersing yourself in cold water, you will experience something called cold water shock,’ McCormick explains (more on that later). ‘This shock can kick-start the immune system, helping to produce more white blood cells and antioxidants, which are proven to boost your immune system and reduce various illnesses, from the common cold to heart disease.’
Indeed, the elation of cold-water swimming far outweighs the discomfort of entering the water, as Caroline Bramwell, experienced triathlete and author of Loo Rolls to Lycra explains.
‘The joys of wild swimming are immense,’ she says. ‘The sense of relaxation floating in the water; the freedom; feeling at one with nature. I swim in secluded bays off the coast of North Devon with other swimmers. My most memorable experience was an evening swim with a group in the dark, under the full moon, enjoying the bioluminescence – sparkles in the water when you disturb the surface). And of course, the campfire and toasted marshmallows after!’
Sounds glorious, right?
Cold-water swimming risks
Of course, while the benefits are enticing, it’s important to be aware of the risks of cold-water swimming, especially in open water such as lakes or rivers, before you leap in.
‘You will only gain the benefits of open-water swimming if you’re doing it safely, by knowing your limits and the consequences if you go too far, too quickly,’ says Thomas Philbey, company director of PTP Coaching Ltd
Philbey points out that some of these risks can start even before you dip a toe into cold water:
Hypothermia refers to a drop in core body temperature to below 35C (normal body temperature is between 36.5C and 37.5C), which can be serious if not spotted and treated quickly. It is a very real risk to open-water swimmers, especially in the chilliest months.
‘The human body starts to cool from the moment exposure starts,’ explains Philbey. ‘For a lot of open-water swimmers, this is the point when you start removing the warm, dry clothes you are already wearing. You then go for your swim – during which time your body continues cooling – and then on leaving the water, while you are drying off and getting dressed, your body will still be gradually cooling down.’
Philbey says that it takes the human body twice as long to warm back up as it does to cool down.
‘This means that, if it takes you roughly seven-and-a-half minutes to get changed and into the water, you swim for 15 minutes, and then it takes you a further seven-and-a-half minutes to get changed back into dry clothes again, your body will have been cooling for half an hour – not just for the 15 minutes you were swimming. It will then take your body an hour to warm back up fully once more.’
Symptoms of hypothermia include:
Cold, pale skin
To treat hypothermia, it’s important to warm up, but not too quickly. Remove any wet clothing (for example, your wetsuit and swimwear), get dried and dressed quickly, and wrap up in blankets. You should also have a warm drink and eat a sugary snack. If symptoms don’t improve, it’s important that someone calls 999.
Cold water shock
Cold water shock is your body’s short-term involuntary response to being immersed in cold water. It causes the blood vessels in the skin to close and your heart to begin to work harder. It also produces the ‘gasp’ response, as well as rapid breathing.
Rest assured, cold water shock only last for around 90 seconds. ‘The best way to avoid cold water shock is to take it slowly when you enter the water,’ advises Philbey. ‘Never immerse yourself by jumping in or dunking straight under the water.’
You won’t get chilblains from swimming in icy temperatures – but they might appear if you warm up again too quickly. These little red bumps on your skin (which often appear on extremities such as fingers and toes after exposure to cold temperatures) are not usually serious, but they can be itchy and uncomfortable.
To avoid them, make sure you don’t warm up too fast after your cold-water swim, for example by putting your hands onto a radiator. If you do develop chilblains, they are unlikely to require treatment and should disappear on their own – just try not to itch or irritate them!
Of course, sadly there is always a risk of drowning any time you enter the water, and even the most competent of swimmers can be caught out if they haven’t taken the necessary precautions. Check out our ‘staying safe’ section below, to help minimise the risks and keep yourself as safe as possible at all times.
Swimming in open water: staying safe
Keeping yourself safe while swimming in cold water comes down to a number of factors, from knowing where to swim, to protecting yourself against the cold, to knowing when to get out!
Following these safety precautions will help you make the most informed choices possible, to ensure your safety – and that of others:
✔️ Think before you swim
As enticing as a body of water can look from land, never make a snap decision to enter the water, especially if you have no knowledge of the tides, currents and other crucial factors. Always do your research first, and check your entry and exit points.
✔️ Consider wearing a wetsuit
Of course, it’s entirely up to you whether you choose to wear a wetsuit or not. Some people are averse to them, even in water below 5C! However, a wetsuit can help to keep you safe and more comfortable in cold water.
‘Wetsuits not only give you additional buoyancy, meaning your body will not be working as hard to stay afloat, but they also provide warmth,’ says Philbey. ‘When a wetsuit gets wet, it traps a layer of water between your body and the suit. As you swim, your body warms that water, providing an additional layer of insulation. Wetsuits are a preventative measure against hypothermia, but they will not make you immune to it.’
✔️ Never swim under the influence of drugs or alcohol
This should go without saying, but never swim when you’ve had a drink or two, or have been taking drugs, as your judgement will be impaired.
✔️ Always swim with others
‘We recommend that you never swim alone,’ advises Philbey. ‘It’s a better idea to swim with a group.’ As well as this, always let others know where you’re going, especially if you’re not swimming in a lifeguarded open-water swimming venue.
✔️ Enter the water slowly
As previously mentioned, entering the water slowly will help protect you against cold water shock. Once in, float on your back for a short while, to help slow your breathing and relax your body, before beginning your swim.
✔️ Consider using a tow float
‘Using a tow float is a great idea – we don’t allow swimmers to enter the lake without one,’ says Philbey.
Indeed, a tow float can be beneficial for a number of reasons: it can act as a float if you are in deep water and suddenly develop cramp, for example; and its bright colour keeps you more visible in the water.
✔️ Know your limits
Being mindful of your individual limits is one of the keys to staying safe in cold water. Never stay in longer that you are comfortable, even if a friend wants to swim for longer, and only swim if you are with others, have done your research and are confident in your own ability.
‘Another good golden rule to stick to is to get out while you’re still feeling great in the water,’ says Philbey. ‘If you wait until you’re tired and shivering, you’ve left it too late.’
Ultimately, it’s mostly all common sense. ‘For me, the top priority of wild swimming is about being safe,’ says Bramwell. ‘Always swim with others who are competent swimmers. I always wear a wetsuit, neoprene shoes, gloves and a hood – it stops you losing heat through your head!
‘Be aware that the cold will affect your breathing, so take time to acclimatise – relax on your back to get your breathing steady. And finally, unless you have built up an acclimatisation to the cold, don’t stay in too long, as your body temperature will drop.’