By Dr. Mercola
The Coney Island Polar Bear Club was founded in 1903 by Bernarr Macfadden, an early advocate of physical fitness and natural foods, who believed immersing yourself in the ocean during the winter was “a boon to one’s stamina, virility and immunity.”1
To this day, club members take weekly dips in the ocean from October through April, a practice that is also embraced by numerous other “polar bear clubs” around the United States and world.
In fact, people in Russia and Scandinavia have been taking so-called polar bear plunges for centuries, often right after coming out of a hot sauna. Participants claim the cold water is invigorating and energizing, but is it really good for your health?
Polar Bear Plunges Come With Real Risks …
Jumping into a body of near-freezing water is not an activity to be taken lightly, and if you do decide to do it, you should be in relatively good shape first. To put it simply, the cold water will generate an enormous shock to your system, which will result in:
- An initial “cold shock,” which will leave you gasping for air and unable to hold your breath
- Blood vessels along your outer body constrict, attempting to shift blood to your inner organs
- Your muscles will get very cold and may become paralyzed or weak
Drowning, even after just one or two minutes, is therefore a very real risk if you’re not careful.
Cold Temperatures May Increase Your Risk of Stroke
For those at risk of stroke, aneurysm, blood pressure problems, or heart disease, the constricting of blood vessels and extra stress on your body can be especially dangerous, increasing your risk of heart attack. Even among healthy people, the adrenaline release that occurs during a polar bear plunge can lead to irregular heart rhythms.
Further, research has shown that when temperatures decline, your blood pressure tends to go up, and this association is particularly strong if you’re over age 80. On average, systolic blood pressure may be up to 5 points higher in winter than in summer.2
This makes sense since, as mentioned, when you’re cold your arteries may constrict, which means your blood must be pumped with greater pressure in order to reach all areas of your body. This is a significant finding, since high blood pressure is one of the largest risk factors for stroke. In other words, exposure to cold temperatures may lead to a rise in your blood pressure that in turn raises your stroke risk.
If you know you have high blood pressure, are at an increased risk of stroke, or are elderly, polar bear plunges may pose too much of a risk for you.
That said, if you’re healthy you may be able to develop a tolerance of sorts to the cold water if you immerse yourself on a regular basis, or “prime” your body for the plunge by taking gradually colder showers for a few days. And it’s also important to immerse yourself in the water gradually, by walking in from a beach as opposed to jumping in from a pier (which leads to such a sudden change in your body temperature that it can cause a heart attack).
Cold Water May Help You Activate Beneficial Brown Fat
Provided it’s done safely, there appears to be some health benefits to cold-water immersions or plunges. In one study, scientists found that they were able to activate brown fat in adult men by exposing them to cold temperatures.3 Brown fat is a heat-generating type of fat that burns energy instead of storing it, and this may have important implications when it comes to weight loss.
Human newborns have a supply of brown fat to keep warm, but by adulthood they lose most of their stores of it. Brown fat has been located in the neck area, around blood vessels (helping to warm your blood), and "marbled" in with white fat in visceral fat tissue. The men burned more calories when cooled, and lost white fat, the kind that causes obesity. According to the study's authors:
"Does human brown fat actually combust fat to release heat? ... Ouellet et al. demonstrate that metabolism in brown fat really is increased when adult humans are exposed to cold. This boosts the possibility that calorie combustion in brown fat may be of significance for our metabolism and, correspondingly, that the absence of brown fat may increase our proneness to obesity …"
Swedish research published in 2009 also found that cold temperatures increased the activity in the subjects' brown fat regions.4 In fact, cold-induced glucose uptake was increased by a factor of 15! Based on animal models, researchers estimate that just 50g of brown fat (which is less than what most study volunteers have been found to have) could burn about 20 percent of your daily caloric intake—and more if 'encouraged.'
Boost Your Body’s Fat-Burning Potential With Exposure to Frigid Temperatures?
Tim Ferriss, author of The Four-Hour Work Week, also published a book called The Four-Hour Body,5 which also includes the concept of activating your brown fat to boost fat burning by exposing yourself to frigid temperatures. He claims you can increase your fat-burning potential by as much as 300 percent simply by adding ice therapy to your dieting strategy. A LiveStrong article backed up Ferriss' claim stating:6
"A NASA scientist told ABC News that's no hyperbole. In studying the effects of temperature on astronauts, he saw people's metabolism boost by 20 percent in environments as mild as 60 degrees. A Joslin researcher told National Public Radio that 3 oz. of brown fat could burn 400 to 500 calories daily."
So, how does Ferriss' Ice Therapy work? Well, by cooling your body down with ice, you're essentially forcing it to burn much more calories by activating your brown fat, as the studies above can attest to. His suggestions, from easy to 'hard core,' include the following. Do advance slowly! It may be inadvisable to go straight to the ice bath if you're not used to it!
- Place an ice pack on your upper back and upper chest for 30 minutes per day (you can do this while reading or relaxing in front of the TV for example)
- Drink about 500 ml of ice water each morning
- Take cold showers
- Immerse yourself in ice water up to your waist for 10 minutes, three times per week. (Simply fill your tub with cold water and ice cubes)
Another Use for Cold Water: Muscle Soreness
Polar bear plunges tend to be regarded as a fun, social activity that may end up giving you a health boost. But regular cold water and ice baths, otherwise known as cold-water immersion or "cryotherapy," is a popular technique among amateur and professional athletes, too, as it is thought to help reduce muscle inflammation and pain after exercise, as well as speed recovery time.
Indeed, after analyzing 17 trials involving over 360 people who either rested or immersed themselves in cold water after resistance training, cycling or running, researchers found the cold-water baths were much more effective in relieving sore muscles one to four days after exercise.7 Just how cold does the water need to be?
In this case, most of the studies involved a water temperature of 10-15 degrees C (50-59 degrees F), which participants stayed in for about 24 minutes. Some of the trials involved colder temperatures or "contrast immersion," which means alternating between cold and warm water (this did not show a significant benefit compared to rest, but some experts do believe that alternating hot and cold water helps drive oxygen and nutrients to your internal organs, while encouraging detoxification).
Most studies on cold-water immersion report no or minimal side effects, so if you're willing to spend 20 minutes or so in a cold tub of water, you may very well find some relief. Of course, common sense must be used and caution exercised. As with polar bear plunges, when you immerse yourself in cold water, it will shock your body to some degree, so you need to make sure the water is not too cold, and that you do not stay in it for too long.
Can Polar Bear Plunges Increase Your Stress Tolerance?
Exposing your whole body to cold water for short periods of time, which is precisely what polar bear plunges entail, is actually used to promote “hardening.” Hardening is the exposure to a natural stimulus, such as cold water, that results in increased tolerance to stress and/or disease. This was demonstrated by a study involving 10 healthy people who swim regularly in ice-cold water during the winter.8 Following exposure to the cold water, researchers noted a:
- “Drastic” decrease in uric acid levels: High levels of uric acid are normally associated with gout, but it has been long known that people with high blood pressure, kidney disease and people who are overweight often have elevated uric acid levels. When your uric acid level exceeds about 5.5 mg per deciliter, you have an increased risk for a host of diseases including heart disease, fatty liver, obesity, diabetes, hypertension, kidney disease and more.
- Increase in glutathione: Glutathione is your body's most powerful antioxidant, which keeps all other antioxidants performing at peak levels.
Personally, I have been experimenting with cold-water immersion for a couple of years. I now go into the shower without allowing it to warm up, and I also jump in the ocean without a wet suit on. I have found that if I hold my breath it really helps adjust to the initial shock, and I rapidly acclimate to the cold. I have come to enjoy it and now view it as a form of healthy stress very similar to exercise.
If you decide to give any type of cold-water immersion a try, be sure to listen to your body and work up to the more advanced techniques gradually.