How a Cold Plunge Can Benefit Your Mind and Body

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While it's fairly common for athletes to take a post-workout ice bath, the practice of immersing your body in freezing cold H2O has become more popular amongst celebrities as of late, too. Lady Gaga, Madonna, and Brooke Shields are some of the stars who've tried versions of the teeth-chatting trend. (Brie Larson even lists cold showers as a fave way to calm down!) But the latest big name to join the cold plunge train? Alyssa Milano.

On Tuesday, the Charmed alumn took to Instagram to share her (chills-inducing) experiences alongside a snap of her kneeling on the edge of a small pool. "This is me about to get into a cold plunge," wrote Milano, 49, in the caption. "It took me 15 minutes to talk myself into getting in it and once I got in…it was just as un-delightful as I thought it would be."

Despite her not-exactly-raving review, the actress hasn't written off cold plunges — at least not yet. "Tomorrow I'm going to try to elongate my exposure time from 4 seconds to 6 seconds. Wish me luck. #coldplunge," she continued in her post.

But if she found the practice to be, in her words, "un-delightful," why would she want to do it again? And what is a cold plunge, anyway? Ahead, experts answer those questions and weigh in on the purported cold plunge benefits.

What Is a Cold Plunge, Exactly?

Whether it's done in an outdoor tub à la Milano or involves soaking in a veritable sea of ice cubes (see: Lady Gaga), a cold plunge is essentially the act of immersing yourself in cold-temperature water (typically 50°F or below). And while it's garnered quite a bit of attention lately (with the eponymous hashtag even racking up hundreds of millions of views on TikTok), the concept is hardly new. In fact, the cold plunge is considered "an ancient practice," says Thea Gallagher, Psy.D., a clinical assistant professor at NYU Langone Health and co-host of the Mind in View podcast. And although it's hard to say exactly where cold plunges started, Greek physician Hippocrates reportedly thought that they could help ease fatigue and they were recommended by doctors in the 1700s to treat things such as fever, according to research.

Most recently, cold plunges have been popularized by people such as Wim Hof, a Dutch motivational speaker and extreme athlete who claims cold plunges (in tandem with certain breathing and meditation techniques) can help reduce anxiety and stress. Hof is such a believer in the healing potential of immersing yourself in freezing H2O that he's created something called the Wim Hof Method: a technique that combines "breathing, commitment/mindset, and exposure to cold water" that, when practiced consistently, can benefit your mental well-being, according to the method's website.

But cold plunges, in and of themselves, have been linked to physical and mental health benefits. And on that note...

Cold Plunge Benefits

"There are so many benefits to cold plunges for your entire system," says Joseph Ciotola, M.D., an orthopedic surgeon at Baltimore's Mercy Medical Center who has trained with Hof. "I do it every day."

For starters, the tactic might help improve your circulation "especially when you alter hot and cold because it improves the elasticity of your blood vessels," says Dr. Ciotola. And the more flexible your blood vessels, the better they're able to regulate your blood pressure and maintain good heart health.

Cold water immersion can also have anti-inflammatory effects on your muscles and joints, which can lower your risk of injury and pain, he adds. In fact, research suggests that exposure to cold H2O decreases skin, core, and muscle temperatures. This can lead to vasoconstriction (aka narrowing of blood vessels), which, in turn, decreases inflammation from muscle damage, according to a 2006 study. What's more, lower tissue temps can cause a reduction in nerve conduction properties and a decrease in muscle spasms and pain.

That being said, there isn't a ton of robust research to directly support the benefits of cold plunges, says Tracy Zaslow, M.D., M.D., a primary care sports medicine specialist at Cedars-Sinai Kerlan-Jobe Institute in Los Angeles and a team physician for Angel City Football Club. Still, one small study from 2004 found that people who suffered from health issues, such as fibromyalgia (a chronic condition that causes pain and tenderness throughout the body) and asthma (chronic lung disease that affects the airways in the lungs), reported experiencing less pain after doing cold water swimming over a four-month period. Meanwhile, research from 2012 and 2016 suggests that cold water immersion (vs. passive recovery) following a workout can lead to decreased muscle soreness.

The mental perks of cold plunges, however, are less clear — from a scientific standpoint, at least. While "the area needs more research, there is some preliminary data supporting its mental health benefits," says Gallagher. For example, a 2021 study of people between the ages of 19 and 88 found that those who swam in the ocean during the winter reported having lower levels of stress and higher feelings of well-being than those who didn't go into the H2O.

What's more, another study of winter swimmers found that people who followed the practice saw drops in self-reported tension, fatigue, memory issues, and bad mood as they swam more. And, after four months, the swimmers said they had more energy and were more active than those who didn't swim. There is a caveat, though: Swimming and exercise alone have been linked to a reduction in pain and improvements in mental health, making this a tough one to parse out, notes Dr. Zaslow. "If you swim even in warm water, you may have some of these effects," she says. "We can't discount that." (Related: How to Safely Dive Into Open-Water Swimming)

While the association between cold water immersion and improved mental health isn't entirely clear, some research suggests that immersing yourself in icy H2O can trigger the release of stress hormones (e.g. cortisol). This could potentially explain the boost in energy post-cold plunge. "Anecdotally, it's rejuvenating," says Gallagher. "It challenges people to see what they can handle."

People can "feel really good afterward," says Gallagher, and that may help alleviate feelings of anxiety and depression. And Dr. Ciotola agrees, adding "you get this endorphin release when you get out." In fact, cold water swimming has been shown to increase the concentration of norepinephrine (which can improve energy and alertness) and endorphin (which can boost mood), according to research. These effects could even help ameliorate depression, according to a 2020 scientific review.

Need not forget, though, that there's also "a lot to be said for the placebo effect," says Gallagher. "If you feel like it's helping, it's helping."

So Should You Try a Cold Plunge?

That's up for you — and your doctor — to decide. "Cold water affects your blood pressure, heart rate, and circulation, and it can cause cardiac stress," says Dr. Zaslow. "In rare cases, it has provoked cardiac arrest. People with underlying health issues are especially at risk for this."

That being said, if your doc does give you the okay and you're interested in bathing in icy waters, start small and work your way up. That means beginning with a tub of H2O that's about 50° F or less, says Dr. Zaslow. You should also aim to submerge yourself — either a specific body part that's particularly sore or your whole body up to your chin — for two minutes and eventually work your way up to 10 minutes, if you can tolerate it, suggests Dr. Ciotola.

"Just remember, though, that nothing is a cure-all, so it should be an adjunctive intervention to a healthy lifestyle," adds Gallagher. (Up next: How Float Therapy Can Benefit Your Mind and Body)