Benefits of cold water swimming explained by health experts—an icy dip is really is so good for you

A cold water plunge is a real tonic. We discuss the many benefits of wild swimming with health experts

older woman in a swim cap enjoying the mental benefits of cold water swimming in a lake
(Image credit: Getty Images )

The benefits of cold water swimming are praised by health experts across the world—despite it initially being a shock to the system. Not only does wild swimming offer the chance to get outdoors and enjoy some fresh air away from chlorinated waters, but regular dips can have an overwhelmingly positive impact on our health. We spoke to health experts and cold water swimmers themselves to find out exactly why this daredevil hobby is worth a try. 

While you can count an all-body workout (in particular, it's a great ab workout), natural pain relief, and a metabolism boost among the physical benefits of swimming in general, cold water therapy can have a big impact on mental health, too. Research from the British Medical Journal (opens in new tab) found that regular cold water swims are a viable alternative to antidepressants, not to mention being an all-around mood booster. 

"Like increasing numbers in lidos, lakes, and seaside locations around the country, I’ve become obsessed"

Miranda McMinn

Combine an intense dopamine hit with all the benefits of ecotherapy, and it's easy to see why so many of us are becoming addicted to open water. Including our editor, Miranda McMinn, who became a cold water convert after braving the icy waters at Hampstead Ladies' Ponds. "Like increasing numbers in lidos, lakes, and seaside locations around the country, I’ve become obsessed," said McMinn, whose perception changed after a lifeguard revealed the key dos and don’ts of cold-water swimming. “She recommended neoprene socks and gloves, never staying in too long, super-warm clothes to get changed into, and, most usefully, having a cold blast in the shower every day at home to keep in the zone." 

For Kristy Field, co-founder of Wiltshire Wild Swim (opens in new tab), wild swimming is such a popular hobby for women due to the community it creates. "I am constantly buoyed up by the sense of camaraderie. It’s like a club for women who put vanity aside for this portion of the day for the sheer joy of the experience. I feel inspired by the 70 and 80-somethings who come regularly—it gives me a sense of hope for active enjoyment of old age."

Cold water therapy—how does it work? 

cold-water swimmers in a calm lake wearing wooly hats

(Image credit: Getty Images)

Mark Harper, a consultant anaesthetist and cold-water swimmer himself, is part of the team at the University of Portsmouth driving research into the benefits of cold-water immersion. He explains that when the face is submerged in cold water, "messages are sent out through the parasympathetic nervous system that put your organs into 'rest and digest' mode, lowering heart rate and reducing inflammation. But also, at the same time, the chemicals, serotonin, and noradrenaline are released, and it's believed that these turn on the pain-inhibiting pathways in the brain". 

Cold-water therapy is nothing new, its origins tracing back to Ancient Greece and the principles of thermal medicine (opens in new tab), where water was used at different temperatures to soothe muscle fatigue and other health ailments. In fact, Hippocrates himself was the earliest recorded champion of an ice-cold dunk, who documented (opens in new tab) his experiences with 'magic waters' for reducing pain. Nowadays, the benefits of cold-water therapy—also known as cold hydrotherapy—are accessed through cold showers, plunge pools, and the increasingly popular activity of cold-water swimming. Cold-water therapy is also used by athletes, with studies (opens in new tab) showing the positive impact on recovery after intense workouts. 

Benefits of cold-water swimming for body and mind

woman swimming in cold-water in the sea wearing a swim cap

(Image credit: Getty Images)

1. Cold water swimming is an instant mood booster

“Apart from the reputed physical benefits of cold-water swimming, the emotional benefits are hard to overstate," Field, of Wiltshire Swim, told us. "The (enjoyable) pain of plunging into freezing cold water is rewarded with a tsunami of endorphins, and afterward, you feel happy as a clam. And once you’ve swum in a 4°C pond, you feel like you can take on anything the day throws at you." This feeling of euphoria is largely down to the release of hormones that help the body respond to stress caused by the shock of cold water. A 2000 study (opens in new tab) carried out by scientists in Prague found that cold-water immersion can boost dopamine—also known as the 'happy hormone'—levels by 530%

And while a mood boost may be instant, research has also explored the long-term mental health benefits of wild swimming. One study (opens in new tab) found that open-water swimming can be used effectively to treat some cases of depression. In this study, the case study—a 24-year-old woman who had suffered from depression and anxiety since she was 17—began a trial of swimming weekly in cold water, which she found reduced her symptoms so much that she was able to come off her usual medication. 

"I love cold water swimming because it never fails to make me feel invincible—even for a short period of time. It helps me deal with work, teenagers, everything that life throws my way. I've never once regretted going for a swim, and often make time to go for a swim when I might not otherwise have planned it," keen cold water swimmer Sally Sellwood told us. "It's almost impossible to describe the sense of calm I get when entering the water—pushing through the initial excruciating cold to the point of full immersion"

2. Shocking the system jump starts your metabolism

A 2014 study (opens in new tab) in the Netherlands linked regular exposure to the cold with cold-induced thermogenesis (opens in new tab) in humans, which, put simply, is the body's ability to generate heat by increasing the metabolism. The study found that more brown fat—also known as brown adipose tissue—is produced by humans in cold temperatures. Brown fat contains more mitochondria (a type of cell), which act as 'engines' to burn calories and produce heat. Brown fat has been a topic of interest in the medical sphere as it appears to use other fat stores as fuel to aid healthy weight loss, though more research needs to be done until we know exactly what this means for the human body. 

3. Wild swimming a full-body workout

Any kind of swimming is effective cardio and strength training, but adding in the complication of cold water makes the exercise more strenuous, as your body is also working hard to keep you warm. “Swimming is one of the most beneficial exercises for people of all ages because it provides a workout for your whole body,” says Sonia Khan, senior pharmacist at Medicine Direct (opens in new tab). “While swimming, your arms, legs, feet, and hands are all needed to stay afloat and move around. For this reason, it makes for a gentle yet comprehensive form of exercise.” 

The added weight of swimming boots, gloves, and (potentially) a wetsuit add to the challenge of open-water swimming, burning more calories. As well as aiding weight loss, this kind of intensive workout is also one of the best sleep aids

4. Improved cardiovascular health

According to David Sautter, NASM-Certified Personal Trainer, one of the top physical benefits of cold water exercise is, "Improved cardiovascular health through giving our heart and lungs and workout". Though he also notes, despite the positive impact of cold water swimming on respiratory health, it's important to know how to breathe properly when in the water. 

“Breathing in open water is going to require some getting used to. You’ll need to try to experiment with breathing on both sides of the body instead of the one side you're accustomed to. Your body might require some getting used to water temperature so I’d recommend starting out with a wetsuit, which will dramatically cut down on the cold.”

5. Cold water swimming could boost the immune system

group of women cold-water swimming in the sea

(Image credit: Getty Images)

While the link between cold-water swimming and the immune system isn't conclusive, there is mounting research (opens in new tab) that wild swimmers are more resistant to certain illnesses and infections. This study (opens in new tab), carried out by Czech scientists, also links cold-water immersion to invigorating the immune system and an increase in white blood cell count and antioxidants. Though more studies are needed to validate these findings on a wider scale. 

6. Reduced pain and inflammation

It's no secret that cold temperatures can be used as natural pain relief—a cold ice pack being the first port of call to reduce swelling. And this isn't without scientific backing. A group of researchers from Hong Kong found in a 2016 study (opens in new tab) that cold-water immersion after exercise can lead to decreased inflammation and pain for up to 24 hours a workout

However, when it comes to tackling chronic pain, much of the evidence citing the healing effects of cold-water swimming is anecdotal, as Anna Deacon and Vicky Allan found when researching Taking The Plunge (opens in new tab). They write, "Back in the 18th century, sea swimming, especially during winter, was recommended for the treatment of a range of diseases. Whole seaside resorts were founded on these perceived health benefits. We still, centuries later, await firm scientific evidence, but anecdotes abound of cold water's pain-relieving benefits. Dawn [a regular wild swimmer who previously struggled with constant pain due to a genetic back condition] for instance, whose turnaround has been phenomenal—from struggling to walk to hiking up to the shelter hut halfway up Ben Nevis and summiting the iconic Suilven." 

"In medical and scientific circles there is a growing interest in whether cold-water immersion may help the pain and inflammation associated with certain chronic conditions"

Anna Deacon and Vicky Allan

"Yet, in medical and scientific circles there is a growing interest in whether cold-water immersion may help the pain and inflammation associated with certain chronic conditions. It's this kind of chronic pain that is at the heart of the Taking The Plunge project. From the moment we started, the personal stories of such cold-water relief gripped us. Even if pain wasn't the reason people were choosing to swim, they were certainly reporting the benefits—people like Lil, who found relief from the ache of her fibromyalgia, and said that following a swim she will 'just dance'." 

7. Wild swimming is effective ecotherapy

woman swimming in a lake wearing swim cap

(Image credit: Getty Images)

We’re fully acquainted with the benefits of nature and just how powerful it can be to escape the stresses of everyday life. Whether you want to reap the benefits of swimming in the sea or take in the serenity of a still lake, wild swimming offers up some idyllic landscapes. 

A large part of the effect is the beauty of being outside in nature—especially for us who live in a city," confirms McMinn. "I’ve swum alongside a brilliant blue kingfisher darting from branch to branch. The resident heron has swooped to land above my head. There are flocks of electric green parakeets and the unfolding annual soap opera of whether the mallard ducklings and moorhen chicks will get eaten by the carp. And that’s all on top of the startling beauty of the changing seasons.”

Between lengths, or while warming up after a quicker plunge, take a moment to observe the wild and natural habitat around you, enjoying a moment of mindfulness. Slowing down and connecting with nature is an effective way to reduce stress, and has also been cited (opens in new tab) by some case studies as a way to alleviate symptoms of depression and even stop panic attacks

8. It builds a sense of community

Perhaps one of the most appealing benefits of cold-water swimming is the sense of community it brings, with fellow swimmers eager to share their experiences. “The group offers mutual support that goes well beyond swimming,” Field explains. “The other side to swimming is that we’re a communal support group. Lots of us joined at difficult times, struggling with different areas of our lives. We’re like family—a swim family."

For Field, open-water swimming also encourages self-acceptance and body confidence. “There’s nothing like seeing a lot of other midlife women in the buff to make you feel totally normal. Unlike at the gym, there’s seldom a G-string in sight, just a lot of sensible pants and necessary fleeces.”

Cold-water swimming—some safety considerations

group of swimmers relaxing after open-water swimming

(Image credit: Getty Images)

Of course, you have to be sensible. Cold-water swimming can be dangerous and can cause cold shock (particularly if you're not acclimatized to the temperature) as well as hypothermia. Common sense dictates you shouldn’t just jump headfirst into a freezing pond in the middle of January without any preparation. Talk to a lifeguard at your local lido, ponds, or on a beach near you before attempting a swim and complete a cold-water induction session before getting started. 

Most community groups operate by the legal framework set out in the Outdoor Swimming Society Swim Responsibility Statement (opens in new tab). This essentially means that swimmers are individually responsible for their own safety when swimming with groups and cannot rely on information or advice given by members. 

“With an informal group, an individual’s safety is nobody’s responsibility but their own," Field tells us. "There are probably no lifeguards in the group and the other swimmers are fairly occupied looking after themselves, so it’s vital that individuals understand that they are solely responsible for their own well-being and safety."

When you are ready to take the plunge, it's important to remember:

  • Wear adequate protection—if swimming in winter, invest in a good-quality wetsuit, neoprene gloves, and boots, as well as a woolly hat. 
  • Acclimatize—it's easier to start your swimming career in the summer months, when waters are warmer, and build up a tolerance over time. Entering waters below 10°C can create a shock response and cause rapid breathing, as well as numbness and pain in the hands and feet. You could also introduce cold showers or baths into your daily routine. Take a look at the Outdoor Swim Society's acclimatization guide (opens in new tab) for more information. 
  • Warm-up immediately—it's important to warm up straight away and stay warm for 20-30 minutes after leaving the water. Remove all cold and wet clothing, wrap up in insulated layers and sip on a hot drink after your swim. 
  • Focus on breathing—in colder temperatures, your breathing may become quicker and shallow, so it's important to have some calming breathing techniques in mind to help you relax. The Wim Hof breathing technique—which involves controlled breathwork to relax your mind and body—may come in useful. As may our guide to how to breathe better
  • Don't stay in too long—particularly if you're new to cold-water swimming. A couple of minutes is enough to reap the benefits. 
  • Get some rest—open-water swimming is a vigorous activity that should be followed by some downtime. Make sure you take the time to recover, ensuring you get all the types of rest you need.
  • Be wary of the risks—the Outdoor Swimming Society advises getting expert medical advice before winter swimming if you have a heart condition, high blood pressure, asthma, or are pregnant.

If you want to try wild swimming yourself, the Outdoor Swimming Society (opens in new tab) has plenty of information on how you can get started and where to find wild swimming spots near you.

Lauren is the former Deputy Digital Editor at woman&home and became a journalist mainly because she enjoys being nosy. With a background in features journalism, Lauren worked on the woman&home brand for four years before going freelance. Before woman&home Lauren worked across a variety of women's lifestyle titles, including GoodTo, Woman's Own, and Woman magazine.