Recently, there’s been a lot of buzz around cold-water therapy. Advocates claim it can do everything from helping you recover from exercise to improving your mental well-being, and critics say the evidence supporting it is inconclusive and that sudden immersion in cold water can be harmful.
Sitting, standing, and swimming in cold water are all forms of hydrotherapy. While there is limited research that supports the use of cold-water therapy for therapeutic purposes, supporters believe it may help with muscle recovery, chronic pain, and certain skin conditions.
Potential risks
Hopping into a cold shower, lowering yourself into a cold tub, or jumping into a cold body of water can feel invigorating. But one reason for that also poses a health risk.
When you suddenly immerse yourself in cold water, you experience a rapid increase in breathing, heart rate, and blood pressure often referred to as the cold shock response. If this causes you to gasp involuntarily while your head is underwater, you could drown. Even in a tub or shower, where you don’t submerge your head, the rapid increase in heart rate and blood pressure brought on by cold water can be harmful if you have a problem with your circulatory system.
What the studies say
Despite the risks, there is some evidence that cold-water therapies may improve your mood, attentiveness, and resistance to disease.
For example, a study published in the journal Biology in January 2023 found that 33 adults who weren’t cold-water swimmers “felt more active, alert, attentive, proud, and inspired and less distressed and nervous” after a five-minute bath in 68-degree water. The study also found that these feelings may have a neurological basis. Scans of the participants’ brains taken before and after their baths showed changes in connectivity between “brain areas involved in attention control, emotion, and self-regulation.”
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A 2022 review of 104 studies on cold-water immersion and swimming found that they could offer protection from cardiovascular and metabolic diseases and have generally beneficial health effects. The authors also pointed out, however, that most of the studies they reviewed “were hampered by the fact that they were carried out in small groups, often of one gender, and with differences in exposure temperature and salt composition of the water.” As a result, they said, “without further conclusive studies, [the health benefits of cold-water immersion and swimming] will continue to be a subject of debate.”
A study published in The Journal of Physiology in 2015 found that cold-water immersion after strength training lessened long-term gains in muscle mass and strength. “Individuals who use strength training to improve athletic performance, recover from injury, or maintain their health should therefore reconsider whether to use cold water immersion,” the authors wrote.
A 2020 study of Korean college soccer players, however, found that cold-water immersion can help them recover after games or practice sessions.
How to take the plunge
If you’re interested in giving cold-water therapy a try, begin cautiously.
To start taking cold showers, for instance, begin by lowering the water temperature at the end of a normal shower until it feels slightly uncomfortable. Then stay in it for a minute or two. Over time, make the water slightly colder and increase how long you stay in it. Eventually, you may be able to hop into a cold shower directly.
For ice baths, start with 68-degree water and stay in it only about five minutes. Over time, you can reduce the temperature and increase how long you stay in, but you shouldn’t lower the temperature beneath 53 degrees, or stay in for more than 10 minutes.
As for cold-water swims, you probably should start by swimming outdoors before the weather gets cold. If you can’t do that, exercise outside and lower the temperature of your showers and baths. Never attempt a cold-water swim by yourself or without whatever you need to warm up after you get out of the water.
The cold, hard facts
Cold-water therapy is becoming more popular, but evidence of its physical and mental health benefits is still mostly inconclusive. If you’re thinking about trying a cold-water therapy, you should talk to your doctor first. If they give you their approval and you decide to go ahead with it, ease into it to make sure it’s safe for you.