Looking to buy a cold tub for yourself? We rounded up our top picks, as well as the most compelling evidence that soaking in cold water may actually be beneficial to your overall health. “Used as a recovery method, the water should probably be under 10°C,” suggests cold therapy expert Mark Harper, M.D., Ph.D. “But just to get the cold buzz without quite so much discomfort, temperatures of over 10°C (and even up to 20°C) will have most of the effect with much less pain,” he adds. Note: 10°C is 50°F. On the topic of stress, intentional cold exposure (as in a plunge pool) is a form of hormetic stressor. In layman’s terms, this is the good kind of stress that actually helps your body to adapt and stay fit and healthy. When you spend a short burst of time each day with an acute stressor like cold water, your body is taken out of homeostasis and your cells are activated to promote stress resilience, repair cellular damage (through processes like autophagy), repair DNA, reduce inflammation, and more. In fact, some experts believe that missing out on hormetic stressors can actually hold you back. “Biologically, the lack of acute stressors prevents the intermittent episodes of cellular ‘housecleaning’ activities that slow aging,” Elissa Epel, Ph.D., director of the University of California–San Francisco Aging, Metabolism and Emotion Center wrote in a 2020 research review1. Additionally, shocking your body with a switch between hot and cold extremes can also improve your health, as longevity expert and Harvard geneticist David Sinclair, Ph.D., explains on the mbg podcast. “Sauna protects you against heart disease if you do it regularly, and cold plunges are increasingly thought to be helpful. What [they do] is activate the production of brown fat, which exists mostly in your back. Brown fat puts out signals that increase your metabolism,” he explains. One in vitro study published in Scientific Reports revealed that stem cells subjected to cold temperatures formed brown fat that can increase calorie burn2, although more research is still needed on the topic. As for the mental benefits, Jono James, cold-water immersion expert and CEO of Odin Ice Baths shared that voluntarily placing yourself in uncomfortably cold temperatures can help build fortitude. “You’re purposely putting yourself in quite a bit of pain because the ice bath is not a pleasant experience, but because you’re choosing to do it, it gives you a sense of empowerment. Since it’s a choice, it also means you’re more resilient to things that are out of your control because you’re choosing to put yourself in this uncomfortable position,” he shares. “It’s important to get the body used to the temperature (a minute or two) before putting your face in," suggests Harper. “And there is nothing to be gained and all to be lost by staying in so long as to become hypothermic. This is dependent on temperature: under 10°C, three minutes is sufficient. But even at 20°C, no more than 10 minutes is necessary.”
