Is swimming in ice water good for you?

Is swimming in ice water good for you?

As the summer begins to loosen its grip on the Northern Hemisphere’s northern hemisphere, many people will soon be able to spend their days at the beach splashing in the water or eating ice cream. For some swimmers, however, the fun is just starting.

” The best part about going to Brighton Beach in autumn is the food. Every week the water is a little colder than the previous. Before you know it, it’s 48 degrees!” Bonnie Schwartz Nolan, a management, operations, and financial consultant, swim coach, and successful English Channel swimmer from New York, tells Popular Science. Since over two decades, she’s been swimming in the frigid waters off Brooklyn.

To train for most marathon swims (a swim over 6.2 miles or 10K), swimmers need to get used to spending time in the cold, since swimmers often cannot wear a wetsuit or tech suit to keep warm and must instead rely on their own bodies.

“Your core body temperature is 98 degrees, so even something like 80 will feel cold after a while,” explained Nolan. To even qualify to swim the English Channel, swimmers must undergo a documented six hour sub 60, or a continuous swim in water that is under 60 degrees Fahrenheit (about 15 Celsius).

[Related: Swimming is the ultimate brain exercise. Here’s why. ]

Open water swimming has even grown to include ice swimming, or swims in waters below 41 degrees Fahrenheit (5 Celsius). For me, it’s all about the challenge,” says Elaine K. Howley, a journalist and accomplished swimmer, in an interview with PopSci. “It’s that uncertainty around ‘can i do it,’ in the same way that marathon swimming.” Howley is an accomplished marathon and ice swimmer who completed an ice mile in 2012 and is currently training for her second.

Some anecdotal “wellness” claims including weight loss, better mental health, and increased libido have been made made by followers of regular cold-water immersion, but what about concrete evidence?

A scientific review published today in the peer-reviewed International Journal of Circumpolar Health finds that taking a plunge in cold water may cut white adipose tissue (WAT) in men and reduce the risk of disorders such as diabetes, but other benefits of ice swimming are inconclusive.

The authors analyzed 104 scientific studies and found an additional impact on brown adipose tissue (BAT). The difference is that WAT stores energy, while BAT burns it. Repeated exposure to cold water or air increases the production of BAT, which is also found in the blubber of marine mammals like whales and seals to help keep them warm.

BAT helps the body burn calories, maintains body heat when it is exposed to cold temperatures, and also helps the body control blood sugar and insulin levels. It generates heat in the blood when it is cold outside. It is located mainly around the neck, kidneys and adrenal glands. According to the Cleveland Clinic, it’s brown because the fat cells are full of mitochondria, which contain a lot of iron. BAT gets its brown color from iron.

Exposure to cold water or air appears also to increase the production of a protein called adiponectin by the adipose tissue. This is a protein that plays a key role in protecting against insulin resistance, diabetes, and other diseases. These studies revealed that repeated cold-water immersions in winter significantly increased insulin sensitivities and decreased insulin concentrations. This was true for both novice and experienced swimmers.

Swimming in cold water also has a major impact on the body and triggers a shock response such as elevated heart rate. Many studies have shown that swimmers who are able to adapt to cold water actually have lower cardiovascular risk factors. Other studies show that the heart still has to work harder. All in all, the authors were inconclusive on the overall health benefits of the “fastest growing extreme aquatic sport.”

“From this review, it is clear that there is increasing scientific support that voluntary exposure to cold water may have some beneficial health effects,” said lead author James Mercer, from UiT The Arctic University of Norway, in a press release.

According to the authors, most of the studies on the health benefits ice swimming has done were limited to a small group of people. They did not consider differences in water temperature, saltiness, or freshness. It is not clear if winter swimmers are healthier than the general population.

[Related: How to avoid (and treat) hypothermia. ]

“Many studies have shown significant effects of cold water immersion on biochemical and physiological parameters. It is not clear if these are good for health. This review suggests that many of the health benefits from regular cold exposure may not be due to causality. Instead, they may be explained by other factors including an active lifestyle, trained stress handling, social interactions, as well as a positive mindset,” added Mercer.

The authors note that the swimmers who participated in these studies ranged from elite swimmers to experienced winter bathers to those who had never ice-swum before. Some were strictly ice swimmers, while others used cold-water immersion post-exercise.

The review also revealed the need to educate people about the potential health risks associated with a dip in cold water. These include hypothermia if a swimmer is in the water too long or jumps in without acclimating, as well as heart and lung issues related to the shock from the cold. It is dangerous to jump into cold water without acclimating.

If swimming in icy water sounds like fun, Howley or Nolan suggest taking longer dips in colder water to get used to it. To help her body adjust to the cold temperatures, Nolan took cold showers, slept outside with the windows open and a lighter blanket.

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