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mbg Co-Founders and Co-CEOs

By Colleen & Jason Wachob

mbg Co-Founders and Co-CEOs

Colleen & Jason Wachob are Co-Founders and Co-CEOs at mindbodygreen, and authors of the book “The Joy of Well-Being.”

Image by Raymond Forbes LLC / Stocksy

May 17, 2023

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Most of the existing research on cold exposure and its many health benefits is on full-body, up-to-the-neck immersion in an ice bath, pool, or other cold body of water. The reason for this is purely practical—it’s simply easier to control all the experimental variables that way. In an immersion tank, you can more precisely measure the effects of cold because you can control the temperature and how much skin is exposed to water versus air, regardless of differences in body weight, height, and surface area, whereas in a shower, you can’t really control for any of those things.

If you have any heart problems or a family history of heart problems, talk to your doctor before trying cold immersion or exposure. The benefits of this practice come from the extremes that it pushes your body to in terms of hormetic stress, but one person’s hormetic (safe) stress is another person’s cardiac stress. In rare cases, cold-water immersion has been linked to dangerous cardiac events1 like heart arrhythmias.

One way to reduce this risk may be to start at higher temperatures, and as your body becomes increasingly adapted to the cold, you can handle lower and lower temperatures more safely. Also, if you have a circulation disorder, like Raynaud’s, this practice probably isn’t for you. Again, when in doubt, it’s always a good idea to talk to your doctor. Be smart about anything you try.

We’ll dive into specific recommendations in a minute, but a general principle—whether you’re going for a walk in the wintertime without a jacket or taking a cold shower—is that the lower the temperature you’re exposed to, the shorter the amount of time you need to be exposed to it.

Keep this in mind when adjusting to how the temperatures might change throughout the year. For instance, in the wintertime, the cold water you can get in your shower could be ten to twenty degrees colder than what you’d get in summertime.

If we’re talking about mood, the answer is immediately. Every instance of cold-water exposure will boost your dopamine2 and norepinephrine3 and may offer benefits like mental clarity and improved mood.

The effects of brown fat take a little longer to see because brown fat itself takes longer to accumulate. No one knows for sure how long; Susanna Søberg, Ph.D., author of an important study on winter swimming and metabolism4, believes that after just one season of swimming twice a week, you may see a benefit. Consistent cold-​water exposure over time will help you build up your brown fat stores and see the greatest overall metabolic benefits.

A cold-​water plunge or an icy shower are certain to wake you up, so common sense tells us that the best time of day for this would be in the morning.

The science behind this is rooted in the fact that after the body’s reaction to that initial cold, it will start to heat up and elevate your core temperature as well as dump adrenaline and dopamine into your bloodstream. This is an added bonus of focus if you have an important morning meeting. But because your body wakes up and becomes more alert as your core temperature rises, don’t try a cold shower right before bed.

Excerpted from The Joy of Well-Being by Colleen Wachob and Jason Wachob. Copyright © 2023 by Colleen Wachob and Jason Wachob. Reprinted with permission of Balance Publishing, an imprint of Hachette Book Group. All rights reserved.