Ice swimming may reduce ‘bad’ body fat, but beyond that

Taking a dip in cold water may lower “bad” body fat in men and lower the risk of disorders such as diabetes, according to a major scientific review published in the peer-reviewed journal. International Journal of Polar Health.

The authors say that many of the 104 studies they analyzed showed significant effects from swimming in cold water, including also on calorie-burning “good” fats. They added that this may protect against obesity and cardiovascular disease.

However, the review was generally inconclusive about the health benefits of taking cold water baths, an increasingly popular pastime.

Much of the available research involved small numbers of participants, often of the same sex, with differences in water temperature and salt composition. In addition, it is unclear whether winter swimmers are in better health or not, says the scientific expert team of review authors from UiT The Arctic University of Norway and from the University Hospital of Northern Norway.

“From this review, it is clear that there is increasing scientific support that voluntary exposure to cold water may have some beneficial health effects,” says lead author James Mercer, of UiT.

Several studies have shown significant effects of cold water immersion on various physiological and biochemical parameters. But it is difficult to assess the question of whether these are beneficial to health or not.

“Based on the findings of this review, many of the purported health benefits from regular exposure to cold may not be causal. Instead, they may be explained by other factors including an active lifestyle, trained stress management, social interactions, as well as a positive mindset.”

“Without further conclusive studies, the topic will remain a topic of debate.”

Weight loss, improved mental health, and increased libido are among the many health and well-being claims made by adherents of regular immersion in cold water or arising from anecdotal cases.

This activity takes many forms such as swimming in cold water during the winter season, and is the subject of increasing interest all over the world.

The main objective of the review was to determine whether voluntary exposure to cold water has health effects in humans. The methodology included a detailed search of the scientific literature.

Studies in which participants wore wet suits, accidental immersion in cold water, and water temperatures above 20 °C were excluded from the review.

Topics covered by studies eligible for review included inflammation, adipose tissue, circulation, the immune system, and oxidative stress.

Immersion in cold water has a huge impact on the body and triggers a shock response such as an elevated heart rate.

Some studies have provided evidence that cardiovascular risk factors are actually improved in swimmers who have adapted to the cold. However, other studies indicate a continued increased workload on the heart.

The review provided insight into the positive links between swimming in cold water and brown adipose tissue (BAT), a type of cold-activated “good” body fat. BAT burns calories to maintain body temperature unlike “bad” white fat that stores energy.

Exposure to cold in water – or air – also appears to increase adiponectin production by adipose tissue. This protein plays a key role in protecting against insulin resistance, diabetes and other diseases.

Frequent immersion in cold water during the winter months significantly increased insulin sensitivity and lowered insulin concentrations, according to the review. This was for both inexperienced and experienced swimmers.

However, the authors note that the traits of the swimmers participating in the studies differ. These ranged from elite swimmers or winter swimmers to those with no previous winter swimming experience.

Others weren’t strictly ice baths but used cold water immersion as a post-workout treatment.

There is also a need for education about the health risks associated with immersion in icy waters, the authors say. These include the effects of hypothermia, and heart and lung problems often associated with shock from a cold.


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