Cold immersion therapy can help reduce muscle soreness, cool you down after exercise, help your immune system and metabolism, and even improve your mood. But make sure your immersion in cold water is brief.

Immersing yourself in cold water has some distinct health benefits, as many health influencers, celebrities, athletes, and trainers will happily confirm.

But what’s the science behind cold water therapy? What exactly are the benefits? And what’s the best and safest way to immerse yourself in cold water?

In this article, we’ll help answer these questions and dig into the research that’s been done on cold water immersion.

Cold water therapy is the practice of using water that’s around 59°F (15°C) to treat health conditions or stimulate health benefits. It’s also known as cold hydrotherapy.

The practice has been around for a couple of millennia. But recent adaptations include ice baths, brisk daily showers, outdoor swims, and cold water immersion therapy sessions.

Supporters of this technique believe that cold water therapy can improve your circulation, deepen your sleep, spike your energy levels, and reduce inflammation in your body.

While anecdotal evidence backs up those benefits, not much research has been done to support these claims.

Cold water therapy does, however, have some benefits that are proven by science. Let’s take a closer look at what these benefits are.

Less muscle soreness

Although researchers are debating the details, studies indicate that athletes who soak in cold water for short periods after exercise have less muscle soreness later on.

A small study conducted in 2011 found that cyclists who completed intense training sessions had decreased soreness after they were immersed in cold water for 10 minutes.

A 2016 study involving 20 participants showed the same thing. Athletes who soaked in a pool of cold water (12°C to 15°C) reported less muscle soreness than those who had no hydrotherapy after exercising.

According to medical experts, the reason cold water helps with pain is that it causes your blood vessels to constrict. This reduces blood flow to the area — for example, an injury you’re applying ice to — which helps reduce swelling and inflammation.

One note: If you’re using cold water to help with muscle recovery, you may want to combine it with strategies like stretching or active recovery.

Faster cooldown if you’re overheated

The research is clear: Cold water immersion can help lower your body temperature much faster than just resting in a cool environment can.

A 2015 meta-analysis of 19 studies concluded that contact with cold water (around 50°F or 10°C) cooled off overheated people twice as fast as recovery without hydrotherapy.

The key is to immerse as much of your skin as possible. This means dunking your whole body in cold water, not just running your wrists under a cold tap.

May ease symptoms of depression

Cold water is not a cure for any mental health condition. But certain case studies suggest that cold open water swimming has helped alleviate symptoms of depression and anxiety in some people.

One such case study involves a woman who had experienced anxiety and depression since age 17. At 24 years old, she began a trial program of weekly open water swimming.

Over time, her symptoms decreased so significantly that she was able to stop taking medication to treat them. A year later, her doctors found that regular swimming still kept her depression symptoms at bay.

In another study, researchers found that a program of short, twice-daily cold showers decreased depressive symptoms. It’s important to note, however, that none of the participants in this study had been diagnosed with depression.

May boost your immune system

There’s some evidence that cold water therapy can stimulate your body’s immune system. This would theoretically improve your ability to fight illness.

In one Dutch study, researchers tested whether people could voluntarily influence their own immune response by practicing meditation, deep breathing, and cold water immersion techniques. The results were positive.

When study participants were exposed to a bacterial infection, the group that used these techniques had fewer symptoms. Their bodies produced more anti-inflammatory chemicals and fewer pro-inflammatory cytokines in response to the infection.

It’s important to note that, in this case, researchers felt the breathing techniques were more influential than the cold water immersion. But they credited cold water with building up a kind of resistance to stress over time.

Other studies have suggested that daily exposure to cold water could, over a period of weeks or months, boost antitumor immunity.

According to health influencers, the effects of cold exposure can boost your calorie-burning capacity. But is there any truth to this claim?

Although more research is needed to determine whether cold water therapy can help with weight loss, some studies have shown that immersion in cold water can speed up your metabolic rate. This is the rate at which your body uses energy and burns calories.

Take the historical example of Korean women who, for generations, have earned their living by diving for seafood in the chill waters off Jeju island. Until the recent transition to modern wetsuits, these women dove into water between 50°F to 70°F (10°C to 25°C) wearing only thin cotton bathing suits.

When researchers studied these women, they found that their basal metabolic rate was significantly higher during their winter diving months than during summer dives.

But does that mean you’ll drop more weight if you take cold baths or showers? The science doesn’t go that far.

A 2009 research review concluded that brief immersions (5 minutes) in water less than 59°F (15°C) did increase metabolism. But there haven’t been any large studies proving that repeated icy plunges result in significant weight loss.

If you want to test the benefits of cold water therapy for yourself, you can try it out in several different ways. Here are some suggestions:

  • Take warm-to-cold showers. Start with warm water and, after a few minutes, gradually drop the temperature.
  • Skip the warmup and go straight to a cold shower. This may be especially helpful if you’ve just finished working out.
  • Immerse yourself in an ice bath: Add ice to water until the temperature is between 50°F and 59°F (10°C and 15°C), and stay submerged for only 10 to 15 minutes. One small 2017 study, however, suggested that ice baths may not be as beneficial as experts had previously believed.
  • Consider a short swim in colder waters. Be sure to follow the safety tips below

Talk to your doctor first

Because cold water immersion affects your blood pressure, heart rate, and circulation, it can cause serious cardiac stress.

There have been a number of deaths, both from cold exposure and heart attacks, during open water swim events. Discuss the risks with your doctor and make sure it’s safe for you to immerse yourself in cold water before you try it.

Have an observer with you

Because your reasoning and emotions can be affected by dangerously cold water temperatures, make sure someone is on hand to monitor your condition when you swim, especially in open water.

Be sure to warm up when you get out

Your body temperature could keep dropping even after you get out of the water, increasing your risk of hypothermia.

The Outdoor Swimming Society recommends taking these steps to warm up safely and gradually if you try open water swimming:

  • Immediately put on a hat and gloves.
  • Get out of your wet clothes and dry off.
  • Dress in warm, dry layers, starting with your upper body.
  • Drink a warm beverage.
  • Have a bite to eat — bonus points for something sweet, since sugar elevates your body temperature.
  • Find a warm place to sit down or, if you feel up to it, walk around to raise your body temperature.
  • Avoid taking a hot shower. The sudden change in blood flow could cause you to pass out.

Keep immersions brief

To get the health benefits of cold water therapy, a few minutes may be all you need. Although you can gradually increase your cold tolerance, there’s no therapeutic reason to stay in cold water longer than a few minutes.

Cold water therapy — whether it’s a quick swim in icy surf, a post-workout ice bath, or a brisk shower — can benefit your health in several ways.

It may help you:

  • cut down on muscle soreness
  • cool down after a sweaty workout
  • get into a better mood
  • aid your immune system
  • boost your metabolism

Some advocates say it can also decrease inflammation, improve your sleep, and sharpen your mental focus. But more research needs to be done to determine if these benefits are supported by science.

If you decide to try cold water immersion, talk to your doctor first to make sure it’s safe for you.

And if you plan to swim in open water, make sure someone goes with you. Cold water can have profound effects on your circulatory system, and you need to plan for short immersions and gradual warmups afterward.