Taking the Plunge: Is Cold Exposure Worthwhile?
Jul 20, 2022 Lisa Fields
Has someone in your social media feed been touting the benefits of cold-water plunges or ice baths lately? Cold exposure has been trending on TikTok and other platforms, with enthusiasts claiming that the practice helps them feel happier, healthier and more energized.
There may be minor benefits to cold-water exposure, but very little research has confirmed the advantages. You may or may not want to withstand the discomfort of a chilly dunk for uncertain rewards.
"Nobody knows exactly why it even helps you," says Dr. Tracy Zaslow, a primary care sports medicine physician at the Cedars-Sinai Kerlan-Jobe Institute. "Maybe it's changes in adrenaline or cortisol—or even dopamine. There are a lot of hypotheses, as opposed to data."
For years, professional athletes have been submerging in post-game ice baths to reduce inflammation and soothe sore muscles. But the practice has expanded to a growing number of non-athletes, many of whom practice advice shared by Wim Hof, an extreme athlete from the Netherlands who's best known for withstanding freezing temperatures while swimming and hiking.
"His name is almost synonymous with the practice, although not everybody's following the specific Wim Hof Method," Dr. Zaslow says. "He's considered one of the leaders of the movement."
Tracy L. Zaslow, MD
Tracy L. Zaslow, MD
"Cold-water immersion is not a completely benign activity. Talk to your doctor to make sure that no harm comes from a fun activity that is intended to help your health."
What research says about cold exposure
The popularity of cold-water exposure has outpaced research into the subject.
Of all the possible benefits of cold exposure, soothing sore muscles may be backed with the most evidence.
“There have been a couple of studies showing that there may be some decreased soreness after people were immersed in cold water for about 10 minutes versus those who did not do any cold therapy,” Dr. Zaslow says. "When you're in cold water, your blood vessels constrict so there's less blood flow to the area, then there's less swelling and inflammation leading to less pain."
Many people claim that cold exposure helps boost moods, but this hasn't been proven.
"The study that showed it might be helpful for mental health looked at people who took a course in swimming in cold seawater," Dr. Zaslow says. "But exercise can improve your mood and wellbeing. To me, it's a soft case that it was the cold water providing the aid."
The same is true of longevity claims. (Picture older men who assert that their morning swim in a cold lake helped them reach their 80s.)
"I haven't studied these claims, but I say it was the swimming," Dr. Zaslow says. "I don't know if the temperature of the water matters. Physical activity has been shown to extend lifespan, so it's hard for me to say if it's physical activity versus the cold."
Some people practice cold exposure to boost the immune system, but the research isn't definitive.
"The idea would be that the cold water is stimulating your immune system," Dr. Zaslow says. "If a decrease in cold or other viral illnesses is noted, it could be the cold-water immersion, but most likely, there are many factors that contribute."
Risks of an icy plunge
Cold-immersion tubs are popping up in gyms, spas and other locations, but are they worth trying? As with other health and fitness fads, ask your doctor first. Risks associated with cold exposure include frostbite, hypothermia, heart arrhythmias and even heart attacks.
"It's not a completely benign activity," Dr. Zaslow says. "Talk to your doctor to make sure that no harm comes from a fun activity that is intended to help your health."
Researchers haven't determined an ideal amount of time to submerge or a preferred water temperature.
"Some studies are looking at freezing temperatures," Dr. Zaslow says. "A lot of them are looking at 50 to 70 degrees, so the recommendations are all over the place."
Best cold-exposure practices
If you're curious about cold exposure, build up your tolerance gradually, and don't stay submerged for more than 10 or 15 minutes to avoid complications.
"Working towards your goal slowly is the way to go," Dr. Zaslow says. "Start with a few minutes at a time and add to that so that you can acclimate yourself over weeks."
Afterward, warming up properly should help you avoid harm.
"When you get out, you want to immediately take off the wet clothes and put on warm, dry layers and drink something warm," Dr. Zaslow says. "You don't want to jump into a flaming hot shower right away. That will cause your blood vessels to relax or dilate, and you could pass out."
Sitting in cold water may not be as beneficial as exercising in cold water, so cold plunge tubs may not be worthwhile.
"A cold plunge tub is like a one-man hot tub, but it's freezing," says Dr. Zaslow. "I would definitely advocate for physical activity to promote strength and health. The exercise is probably the big key to gaining health benefits, whether immersing in cold water or not."