Contrast therapy continues to gain popularity as a natural and effective way to alleviate pain, reduce inflammation, and promote overall well-being. Essentially, this therapy involves moving the body between hot and cold treatments — like from a sauna or hot tub to an ice bath or cold plunge.
While it’s typically used by athletes seeking faster recovery, non-athletes can easily use this therapeutic method as well. Here’s what you need to know about the science behind contrast therapy, the risks involved, and a guide to trying it for yourself.
What Is Contrast Therapy?
Contrast therapy involves alternating between constrasting hot and cold temperatures. First, the body is exposed to heat through a sauna or warm bath, which causes the blood vessels to expand, increasing the flow of blood and oxygen. Then, the body is exposed to cold through a low-temperature water immersion or ice bath, which causes blood vessels to constrict. The lymphatic system also dilates and contracts when exposed to hot or cold temperatures, which can move stagnant lymph fluid, activating the body’s waste system. (Extreme temperatures over a long period of time, however, can cause lymphedema, or swelling, for those who are prone to it.)
This process can be repeated several times, alternating hot and cold for as little as 30 seconds up to a few minutes. Contrast therapy timing and temperatures depend on your health needs and goals, so it’s always a good idea to work with a healthcare provider before exploring the practice.
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5 Health Benefits of Contrast Therapy
Contrast bath therapy can be helpful for a variety of health and wellness reasons. Here are some of the potential benefits.
1. It Can Ease Pain
Contrast therapy can help reduce pain by increasing blood flow and reducing inflammation. As physical therapist and certified strength and conditioning specialist Jasmine Marcus tells DailyOM, contrast baths have been shown to work better than cold or hot baths alone at alleviating delayed onset muscle soreness (DOMS), which is the muscle soreness you experience after a workout where you’re challenging your muscles to the point of soreness, whether that’s through weightlifting or power yoga.
There are also more specific, research-backed pain relief benefits. “For example, contrast baths also seem to be better at decreasing knee osteoarthritis pain compared to [only] cold or hot baths,” Marcus says, according to research published in the American Journal of Nursing Science in 2019. Another study found that a regimen involving contrast therapy to treat plantar fasciitis can be just as effective as steroids for alleviating pain.
2. It Can Promote Healthier Skin
According to board certified dermatologist Jennifer Haley, MD, regular sauna use improves epidermal barrier function, creating a healthier protective skin barrier and increasing skin hydration. By adding in the cold element with contrast therapy, she explains, it further boosts skin health by promoting what’s called autophagy, which is essentially the body’s cell recycling system. When cells start to break down, autophagy reassembles the usable parts of these old cells into new cells.
“This process deteriorates with age,” Dr. Haley says. Autophagy affects all the cells in the body, and therefore all of our organs. When the cells in the body are able to turn over and regenerate effectively, it shows on our skin, since the skin is a representation of the internal health of all the organs. Therefore, she adds, improving overall cell function can have a subsequent “anti-aging” effect.
3. It Can Improve Circulation
The expansion and contraction of blood vessels through hot/cold therapy can improve circulation and blood flow, says certified personal trainer and wellness expert Macy Westlund, and that helps deliver oxygen and nutrients to the tissues and promote healing.
While this is a full-body benefit, Haley adds that there’s an indirect positive effect on the skin here as well. “Hot/cold contrast therapy enhances blood circulation and stimulates the lymphatic system by delivering oxygen and nutrients to the skin, removing metabolic waste, and reducing inflammation,” she says. This helps skin look healthier, giving you that coveted glow. (And if millions of #faceicing TikToks can be believed, using ice or tools like an icy roller on your face can calm, brighten, and depuff skin.)
4. It Can Lead to Greater Longevity
While more research is needed, Westlund tells DailyOM that contrast therapy may promote longevity by reducing oxidative stress, which refers to an imbalance between antioxidants and free radicals (unstable atoms that can damage cells, causing aging and illness) in your body. While free radicals — also known as reactive oxygen species (ROS) — aren’t inherently bad, too many of them can cause oxidative stress. An overproduction of free radicals can occur because of external factors like environmental pollutants or heavy metals, or internal factors like inflammation, mental stress, and simply aging.
“High levels of ROS can damage cells and contribute to the aging process,” Westlund says. “Studies have shown that hot and cold therapies could help alleviate oxidative stress in the body by reducing the impact of free radicals, potentially slowing down the aging process.”
5. It Can Boost Your Mental Health
Research shows that cold-water swimming improves memory and mood, as well as reduces pain and tension. Another study found that cold-water therapy can increase dopamine and decrease cortisol, the stress hormone.
Heat therapy can reduce the symptoms of depression and anxiety, according to research. “The warm temperature of hot therapy can help promote relaxation and reduce muscle tension, while cold therapy can stimulate the nervous system and increase alertness,” Westlund says.
Combining these two therapies can have even more of an impact on physical and mental health, many experts say, though more research is needed to fully understand which water (and temperature) therapies are truly superior.
What to Know Before Trying Contrast Therapy
If you’re interested in trying contrast therapy, be sure to do the following before taking the (literal) plunge, advises Westlund. By keeping these things in mind, you can help ensure that you’re using contrast therapy safely and effectively.
Consult your healthcare provider
Talk to your clinician before trying contrast therapy so they can help you determine whether this therapy is safe for you and provide guidance on how to do it correctly.
There are people who should not participate in contrast therapy, such as those with circulatory conditions (like Raynaud's disease, hypertension, or peripheral artery disease), skin conditions (like eczema), diabetes, or nerve damage. Pregnant women are also advised against contrast therapy, as the extreme temperatures could affect fetal development.
Be prepared to monitor your body’s response
While contrast therapy can be beneficial, it’s important to pay attention to your body’s response and stop if you experience any discomfort, pain, or other adverse effects.
Hydrate — and stay hydrated
Contrast therapy can be dehydrating, so always drink plenty of water before and after each session.
How to Try Contrast Therapy
There are many ways you can try contrast therapy, depending on what you have access to. You can use a shower, bathtub, sauna, hot tub, ice bath, cold-plunge pool, or a combination of these. Or you might visit a local spa that offers a plunge pool and sauna to try contrast therapy in a more zen setting.
The simplest way to start, however, is to just use your own shower, says certified strength and conditioning specialist and high-performance coach Jarrod Nobbe, who spoke with DailyOM for this article.
He suggests taking your shower with normal heat, then turning the water on cold — as cold as possible while still being tolerable — for 30 seconds. Then switch the water to hot — not scalding — for another 30 seconds. You can repeat this cycle for up to three to five minutes.
You can also do this with a bathtub by filling it with cold water and adding ice (again, making the water as cold as you can withstand), and then alternating to hot by jumping into a hot shower or turning the shower head on hot, repeating the same cycle as above.
Contrast therapy can help reduce pain by increasing blood flow and reducing inflammation.
“The first few times you try contrast therapy, you might be more sensitive to hot and cold temperatures,” Nobbe says. “As you become more acclimated to this method, your sensitivity will acclimate, and you’ll tolerate hotter or colder water, lengthier times, and more rounds of contrast therapy.” As with any health-related practice, always listen to your body’s needs, don’t overdo it, and be mindful not to turn the water hotter or colder than you can stand. While a little discomfort with cold water is normal unless you’re a polar bear, the hot water should never be scalding.
Nobbe suggests implementing a daily contrast therapy session. “A morning contrast shower is an excellent way to wake the body up, get blood flowing, and activate your circulatory system,” he says.
Of course, taking a contrast shower, or doing contrast therapy using a sauna and cold plunge, will take some time to get used to. Stepping out of your comfort zone and simply trying a 30-second cold burst in your daily shower can be a great way to dip your toe into this wellness method and reap some of its benefits.
