These days, it can seem like there are more types of workout recovery methods than there are actual workouts. You’ve got cold plunges, saunas, massage, cupping—even chocolate milk! 

We get it: When you’re working out regularly at a high level, you want to make sure you feel good enough to go at it again tomorrow. So it’s only natural if you’re curious about whether or not techniques that elite athletes swear by could work for you too.

Take contrast therapy, for example: This process of alternating between hot and cold water immersion is a go-to treatment for professional athletes. (In fact, professional football player TJ Watt told us he often turns to contrast therapy after a workout!) But is a contrast bath a good idea for the average gymgoer, cyclist, or runner?

We spoke with a sports medicine physician and a physical therapist to find out. Here’s everything you need to know about how contrast therapy works, its potential benefits and drawbacks, and how to try it at home.

What Is Contrast Therapy?

Contrast therapy, sometimes called contrast bathing, typically involves alternating between cold and warm immersion—think: ice bath to hot tub and back again. You can immerse your entire body or just a single body part, explains physical therapist Rachel Stinson, regional director for FYZICAL Therapy & Balance Centers in Oklahoma. “Typically, the individual alternates between a warm bath and a cold bath, with cycles lasting a few minutes each. The process often concludes with cold immersion, and the treatment usually lasts 15–20 minutes,” she says.

Typically, the hot water should be about 98–104 degrees Fahrenheit and the cold water should be about 50–59 degrees, says Babak Shadgan, MD, PhD, a professor in the department of orthopaedics at the University of British Columbia who has researched contrast baths, who also serves as chair of the United World Wrestling’s Medical Commission.

Contrast therapy is a relatively common practice in sports medicine, although more research is needed to fully understand its effects and to fine-tune the optimal temperature and time to soak, according to Dr. Shadgan’s 2018 study in the Journal of Athletic Training.

How Contrast Therapy Works

Alternating between a cold plunge and a hot tub might sound like a relaxing way to spend an afternoon at a spa, but there are also some very real physiological changes happening in your body when you take a contrast bath. 

“The alternating temperatures create a ‘vascular pumping’ effect,” Stinson says. Here’s how that works: The warm water opens your blood vessels (called vasodilation), bringing more blood, oxygen, and nutrients to your muscles and other tissues. Then cold water narrows your blood vessels (called vasoconstriction), taming inflammation and swelling, she explains. 

All together, these changes “may help increase blood flow, deliver more oxygen to tissues, reduce swelling, remove waste products, and speed up healing,” Dr. Shadgan says.

Benefits of Contrast Therapy

As you can see from the physiological underpinnings of contrast therapy above, the practice has the potential to ease swelling and speed up recovery for aching muscles. Stinson says she recommends contrast therapy for the following perks:

The improved blood flow from the pumping effect is at the core of all these effects, Dr. Shadgan explains. “This process flushes out metabolic waste, such as lactic acid, while simultaneously delivering oxygen and nutrients to fatigued muscles. As a result, athletes experience reduced muscle stiffness, faster recovery, and improved functional performance,” he says. 

In some smaller, older studies, athletes appeared to recover better after contrast bathing compared to ice baths alone or no special recovery treatment. That said, there isn’t much evidence supporting all these benefits, according to a Physical Therapy in Sport review, and more research is needed. 

One promising area, though? “Contrast bathing interventions may also promote neuromuscular recovery, helping to restore muscle coordination and proprioception [the ability to sense your body’s movements] following strenuous activity,” Dr. Shadgan adds. Because coordination and proprioception help you stay stable and balanced during exercise, “this could be particularly beneficial in preventing injury recurrence in athletes who engage in repetitive, high-impact movements,” he says.

Drawbacks of Contrast Therapy

For most healthy adults, “contrast therapy is generally safe,” Stinson says. That said, certain people need to be a little cautious and others need to avoid it altogether due to some potential health concerns of the practice. It’s worth talking to a healthcare provider before you try it, especially if you have any pre-existing health conditions, Dr. Shadgan says.

For example, if you have heart disease, you may need to skip contrast therapy entirely. “The sudden expansion and constriction of blood vessels can put additional strain on the heart,” Dr. Shadgan explains.

It can also throw your body’s natural blood pressure regulation out of whack, Dr. Shadgan says, which makes it important that pregnant people avoid contrast bathing too, he adds. (Keep in mind the American College of Obstetricians and Gynecologists recommends avoiding extreme temperatures from hot tubs and saunas during pregnancy anyway.)

People with circulation issues like Raynaud’s disease or diabetes should also avoid contrast bathing because “cold exposure can worsen circulation problems,” he says.

If you have neuropathy (aka nerve damage), you need to be extra careful: With reduced feeling in your extremities, you might not be as attuned to the temperature of your contrast baths, which could put you at risk of burns or frostbite, Dr. Shadgan says.

Wait to try contrast therapy for at least a day or two after an acute injury, like spraining an ankle, Stinson says. The temperature change might worsen your swelling; you’ll likely get better relief with rest, ice, compression, and elevation, she says. 

The same goes for any open wounds, skin infections, burns, or eczema flares, Dr. Shadgan says. Wait until these skin conditions clear up, because contrast therapy “can worsen irritation and delay healing,” he says.

When Should You Try Contrast Therapy?

Ready to try a contrast bath? You’ll get the biggest benefits of contrast therapy after physical activity, like a workout or a long day on your feet, Stinson says. It can help you get on your way to recovery so you’ll be ready for your next bout of activity.

More specifically, Dr. Shadgan recommends trying contrast bathing about an hour after a high-intensity workout for optimal performance-related results. That said, any time within 24–48 hours after activity can help ease muscle soreness, he says.

Can You Take a Contrast Bath at Home?

Yes, you can try contrast therapy at home. It just requires a little bit of equipment and a convenient set up. 

If you’re in one of the high-risk groups highlighted above, make sure you have your doctor’s approval before you give it a try. Once you’ve got the green light, “this straightforward method can be a safe and effective choice for muscle recovery and relief from soreness,” Dr. Shadgan says.

He recommends setting up two containers—and you’ll want them to be large enough that you can submerge the intended body parts in them, whether you want to do a whole-body soak or tend to achy feet after a run. Fill one tub with hot water and one with cold water. You’ll want to have a thermometer handy that you can use to measure the temperatures. Remember, you’re aiming for 98–104 degrees Fahrenheit for the warm container of water and 50–59 degrees for the cold H2O.

For optimal contrast therapy timing, you’ll want to regularly switch back and forth between the tubs. Start by immersing the affected body part in the hot water for three to four minutes, then switch to the cold water for one minute. Repeat this cycle for about 15–20 minutes, Dr. Shadgan says, and make sure you finish in the cold water to maximize the recovery benefits. 

Sure, this isn’t quite as scientific as what a sports medicine doctor or physical therapist would offer, but it should still provide similar, if not exactly the same, benefits. “Although at-home contrast bathing can help alleviate muscle soreness, improve circulation, and support recovery, it may not be as precisely controlled as in a clinical setting where therapists monitor temperature, timing, and targeted application,” Dr. Shadgan says.

The Takeaway

Contrast therapy is a process of alternating between submerging your whole body or an affected body part in hot and cold water at 98–104 degrees and 50–59 degrees Fahrenheit, respectively. This creates a pumping effect in your blood vessels that’s thought to bring more oxygen and nutrients to your muscles, potentially reducing inflammation, easing soreness, and speeding up recovery.

While contrast bathing is generally considered safe, people with heart disease, circulation issues, nerve damage, acute injuries, skin conditions, or who are pregnant may need to skip the contrast bath (or at least get a doctor’s OK before trying it). If you’re in the clear, you can try it under the supervision of a healthcare professional or at home in the 48 hours after a tough workout or a long day to help you relax and recover more quickly.

And don’t forget about other workout recovery tools such as stretching, foam rolling, and meditating, all of which are available on the Peloton App.