Cold Plunge: What You Need to Know about the Restorative Practice

While cold plunge therapy, or cold water immersion (CWI), has become a popular trend in recent years, it has been around for centuries. Ancient Greeks prescribed cold water to treat fever and, as early as the 18th century, physicians in Europe began promoting CWI for all sorts of ailments. Today, professional athletes and recreational fitness enthusiasts alike use cold plunge therapy to reduce post-workout muscle soreness and expedite recovery. The cold restricts blood vessels, slowing the flow of blood throughout the body while reducing inflammation and numbing pain signals.

Research has also linked CWI to physical and mental health benefits, such as sharper focus, enhanced mood, better sleep, and improved immune function. Here's what you need to know before you take the plunge and begin reaping some of these rewards.

Do I need a special tub or pool?

There are many different specialized cold plunge tubs or pools on the market. These offer convenience and practicality, cooling the water and keeping it at a consistent temperature. However, these can cost thousands of dollars. If you're interested in CWI and not yet ready to spend that kind of money, you can partially replicate the feeling—and glean some of the benefits—by taking a cold shower or filling a bathtub with ice.

What is the ideal temperature?

There are differences of opinion on the perfect temperature for CWI, but most experts suggest in the range of 10 to 15 degrees Celsius (50 to 59 degrees Fahrenheit). Beginners should start with a higher temperature to give their bodies a better chance to adjust, whereas some experienced cold plungers go as low as 3 degrees Celsius. Older adults and people with asthma or heart conditions, however, should consult with a physician before attempting a cold plunge.

How often should I take the plunge?

Taking a cold plunge for the first time can be challenging. You should resist the temptation to get out immediately, and try to stay for at least 30 seconds, eventually working your way up to 5 minute sessions. You can perform CWI every day after a workout, but just 11 minutes per week is all that's needed for maximum health benefits, according to Susanna Søberg, the author of Winter Swimming.

What is contrast therapy?

Contrast therapy is an increasingly popular wellness practice that involves spending time in heat and cold water, like a sauna or hot tub and a cold plunge pool. Whereas cold exposure tightens blood vessels, heat exposure promotes increased blood flow. Alternating between the two causes your blood vessels to expand and contract, accelerating circulation and enhancing muscle relaxation.