Research shows that subjecting the body to drastic changes in temperatures may have physical benefits, such as pain relief, reduced inflammation, and improved circulation. But what about alternating between extreme temperatures?
This method of switching from hot to cold (or cold to hot) temperatures, often going back and forth several times, is called contrast therapy, or contrast bathing, and has its own set of purported health benefits.
Contrast bathing is a tool that’s been used by athletes for decades to relieve pain and soreness and recover from intense physical activity. Now, experts are touting contrast therapy as a wellness practice that everyone can benefit from, especially for fighting inflammation and slowing down the aging process.
But is this practice really worth all the hype? And what’s it like to subject your body to such extreme temperatures back-to-back? To find out, I decided to take the plunge (literally) and speak to some experts on the topic.
The health benefits of contrast bathing
There are different benefits for hot therapy and cold therapy treatments. For starters, heat exposure boosts heart rate and causes blood vessels to dilate. This, in turn, causes you to sweat and induces effects similar to moderate exercise, according to Frank Lipman, MD, a leader in functional medicine and author of The New Rules of Aging Well: A Simple Program for Immune Resilience, Strength and Vitality.
Dr. Lipman recommends using an infrared sauna specifically. “Infrared saunas heat with infrared light and warm the body from the inside, not just on the surface,” he explains. “You’ll still sweat like a prize fighter but with less heat-related discomfort than you’d experience in a traditional sauna.” He recommends getting your doctor’s okay first, but says “time spent in an infrared sauna can be a safer and more comfortable way to gently work up a good sweat.”
Infrared saunas run approximately 120-140 degrees Fahrenheit. This type of heat exposure may help combat aches and pains, boost immunity by briefly raising the body’s core temperature, and stimulate blood flow.
In a 2016 study of Finnish men, those who used a sauna four to seven times a week were 66 percent less likely to be diagnosed with dementia than those who only used a sauna once a week. Related research also found that frequent sauna bathing was also associated with a reduced risk of mortality related to heart disease.
When you add cold therapy to the mix, contrast bathing can lead to increased circulation, which may help decrease muscle soreness, reduce fatigue, and relieve pain. As Healthline explains, when your body is in cold water, your capillaries (small blood vessels) get smaller, and when you are in warm water, your capillaries open up.
Some contrast bathing enthusiasts believe these circulatory changes—the pulsing action of your blood vessels opening and closing—is what leads to the injury-relief benefits because the increase of blood flow allows for faster cellular recovery. In fact, a meta analysis published in 2017 found that contrast bathing helped athletes recover from fatigue after events.
Physical therapist Leada Malek, DPT, SCS, says that contrast bathing is more effective for recovery than passive rest after exercise, “though you may have to be exercising at elite levels for this effect.” Moderately active people might find just as much of a recovery benefit with other modalities like stretching and compression, she says.
At the very least, however, contrast bathing could offer a mental boost. A 2013 paper in PLOS ONE states that “water immersion may offer a generic psychological benefit whereby athletes simply feel more ‘awake’ with a reduced sensation of pain and fatigue after exercise.”
Can contrast bathing actually slow down the aging process?
Much of the research on contrast bathing focuses on recovery, especially for athletes, but Dr. Lipman says contrast bathing can also boost the health of your cells, which slows down the aging process.
Cold exposure in particular has been shown to increase the production and health of the mitochondria in mice. Mitochondria are the powerhouses of the cell, and as Dr. Lipman explains it in his book The New Rules of Aging Well, they are “the essential force of life and longevity.”
“Mitochondria transform food and oxygen into ATP, or adenosine triphosphate, a type of molecule that powers biochemical reactions,” he explains. “ATP molecules are especially abundant in the cells of your heart, brain, and muscles.” This is why mitochondrial function is so important for overall health and longevity.
Contrast bathing may also boost autophagy, which is how the body repairs damaged cells. Dr. Lipman explains that when cells become damaged, the autophagic process kicks in, “recycling” the still-good parts of the cell to create new, healthy cells.
“Autophagy can be likened to a cellular fountain of youth, delivering an impressive array of preventative benefits protecting us from dysfunction and disease,” he says. Autophagy has many preventative health benefits, such as controlling inflammation, boosting immunity, and yes, regulating mitochondrial function.
What it’s like to do contrast bathing IRL
Luckily for my own curiosity and for the sake of journalism, my gym, Equinox Wall Street, had recently gotten a cold plunge tub that sits near the heated jacuzzi tub and dry sauna.
Although I had frequented the sauna and jacuzzi before, I wasn’t sure if I was up for the challenge of sitting in a cold plunge. Yet, clad in a one-piece bathing suit, I headed to the jacuzzi, which was about 102 degrees Fahrenheit, and stayed in for about 20 minutes. Then I moved on to the dry sauna, which was about 180 degrees Fahrenheit, for a little over five minutes. So relaxing! I didn’t want to get out to subject myself to something uncomfortable, but I knew I had to complete my experiment.
As soon as I got in the cold plunge, the freezing water stung my bare legs. The water was 47 degrees Fahrenheit, which doesn’t sound that bad, but I’ll be the one to tell you that it’s really f’ing cold. I only submerged up to the top of my legs and lasted 20 seconds before getting out. I went back to the dry sauna for a few more minutes and decided to try again; although I was able to get up to my mid-torso the second time, I only lasted 15 seconds before calling it a day. Although I did notice an immediate mental boost, I ended up taking a hot shower in the locker room to heat back up.
A couple weeks later, I wanted to see if I could make it to a full minute. So I started again in the jacuzzi for 10 minutes, followed by the dry sauna for 10 more minutes. Once the cold plunge was available, I got in. I submerged up to just below my boobs, but kept my arms outside the tub. Let me reiterate that it was really f’ing cold, but I managed to make it a full minute!
I found that slowly moving my legs up and down within the tub (while still underwater) helped make it more bearable. Also, breathing is key—my breathing pattern could only be described as “a Lifetime movie actress going into labor in a made-for-TV movie,” but it definitely helped.
I know many people recommend ending on cold, but I couldn’t fathom the idea of just going back to the locker room and changing into my street clothes after freezing my buns off. So I ended with another few minutes in the dry sauna, which made the whole experience more tolerable.
Overall, I did feel invigorated. That second day, I had been up since 4:30 a.m., and even after my cold plunge at around 9 that morning, I had plenty of energy all day. I did notice that I felt a little clearer when it came to focusing and getting work done (let me preface this by saying I also take Vyvanse for my ADHD, which is helpful for this, too). But there’s no denying the immediate mental boost I experienced after getting out of the cold tub.
Is contrast bathing worth it?
I know I’m in a privileged position to belong to a gym that has a jacuzzi tub, dry sauna, and cold plunge, so I do plan on adding this to my routine a couple times a week. The cold plunge is definitely a test of mental resilience; I’m determined to work my way up to two minutes with my arms in the tub. The fact of even lasting a full minute is enough to instill confidence in myself.
I am by no means a hardcore athlete, so I’m not sure how beneficial contrast bathing will be for my fitness recovery. But if it can help my muscles after my strength workouts, that’s an added bonus. And the potential anti-aging benefits that Dr. Lipman outlined are enough to keep me coming back for more.
How to do contrast bathing safely and effectively
While not everyone has access to cold plunges and saunas, don’t let that deter you. Contrast therapy can be as simple as ending your hot shower with a minute or two under cold water, or stepping outside in winter for a few minutes after being in a warm indoor space.
Jordan Crofton, family nurse practitioner and director of patient care at THE WELL, says she frequently recommends contrast bathing to patients. Her personal regimen is 10 minutes in a steam room followed by 10 minutes in a sauna, and then a few minutes in a cold plunge with breathwork (to help her body relax, since extreme cold can shock the system). She repeats the circuit two to three times.
If you’re trying this at home, Dr. Malek suggests starting out by spending one minute in a hot bath, followed by one minute in cold water, and alternating for five to 15 minutes, about an hour after exercise. The hot water should be between 95 and 100 degrees Fahrenheit, and cold between 55 and 60 degrees. Just don’t spend more than a few minutes at a time in the cold water in order to prevent cardiac distress and other negative side effects—cap it at three to five minutes, tops.
Crofton mentions that some companies offer at-home infrared sauna experiences, like HigherDOSE’s infrared sauna blanket, which you can do at home and follow with a cold bath or shower. Clearlight also makes infrared saunas you can install in your home.
Still unsure? Start out by ending your hot shower with 30 seconds of cold water. If you like how that makes you feel, then you might be ready to take the full contrast bathing plunge (literally).