Cold plunge therapy is enjoying its moment in the spotlight. The likes of Lucy Charles-Barcley and seemingly every social media influencer on the internet are promoting the practice of taking a plunge in frigid waters on a regular basis.
If you browsed social media recently, you might be under the impression that everyone has installed an ice bath in their backyard and are starting every day with a frigid dip! But is it just the latest health trend or are there true benefits to this torture…errrr… practice?
What is Cold Water Therapy?
Also called cold hydrotherapy, cold water therapy is the practice of submersing yourself into water around 59 degrees F (15 degrees C). While the practice has been around for many centuries, it has become very popular recently.
You've probably seen social media influencers and athletes taking cold ice baths, but cold hydrotherapy can include cold showers, outdoor swims in cold water, cryotherapy, or structured ice bath therapy sessions.
What are the benefits of cold hydrotherapy?
Supporters of this therapy believe cold hydrotherapy can improve your circulation, help you enjoy better sleep, boost your energy levels, and reduce overall inflammation in your body. Some people claim it can also boost your metabolism and immune system.
While there is anecdotal evidence that some of these benefits may be real, very little scientific research has actually been conducted to validate the claims. However, there are some benefits of cold hydrotherapy that are backed by science.
Reduce muscle soreness
Most endurance athletes are familiar with the practice of icing sore muscles to reduce inflammation and soreness. This can be particularly helpful when you're in a big training block or increasing your training load.
Structured scientific studies do indicate that soaking in cold water for short periods after exercise can reduce muscle soreness for athletes.
A small study on cyclists in 2011 found that athletes were less sore after intense training sessions when they added a 10-minute soak in an ice bath after their session. A similar study in 2016 revealed the same results.
Why does cold hydrotherapy reduce soreness? Medical experts say cold water causes your blod vessels to constrict, reducing blood flow to affected areas – similar to using ice to reduce swelling around an injury. Restricting blood flow to the peripheral areas can improve oxygenation of muscles and boost overall recovery. Many elite athletes and professional teams incorporate cold therapy in their recovery protocol.
Regulate the nervous system
Whether you're taking a cold shower, doing a full plunge in an ice bath, or splashing cold water on your face, exposure to cold water stimiulates the vegas nerve.
The vegas nerve is the main nerve for the autonomic nervous system. It's responsible for regulating your heart rate and breathing. That's why you gasp when getting into cold water – some people even hyperventilate.
A number of psychologists and counselors recommend variations of cold water therapy to aid in the treatment of anxiety, depression, addiction, and more. While the evidence for mental health or mood benefits are mostly anecdotal, qualitative data, and rooted in just a few small studies, scientists see promising research opportunities.
Boost the immune system
You may hear a lot of people claiming that a regular cold plunge can strengthen your immune system. Some studies have revealed changes in white blood cells, suggesting that the immune system could be getting a bit of a boost. However, the studies were measuring biological markers, not actual illnesses so the real-world significance is a bit unclear.
Additionally, research mostly studied experienced cold water swimmers, so it's difficult to parse out the effects of fitness and exercise vs cold exposure.
Overall, there are mixed results regarding any immune benefits. Although, we are certain what happens when you're exposed to cold water for too long! You run the risk of hypothermia and a suppressed immune system.
Improve Metabolism
Researchers at the Arctic University of Norway (even the name sounds cold) observed some metabolic increase in individuals after cold hydrotherapy. However, the sample size of the study (and most others) was very small.
Scientists don't yet have substantial evidence that cold therapy boosts your immune system. Additionally, little is known about how cold therapy impacts body fat percentages and weight loss.
The hypothesis that cold therapy boosts your metabolism is connected to brown adipose tissue, a type of body fat that can produce heat when exposed to cold temperatures. That process of generating heat obviously requires burning more calories.
Is Cold Hydrotherapy Safe?
It's best to speak with your health care provider before incorporating any new therapies–including cold therapy–into your routine.
Regardless of your health status, cold therapy is nothing to take lightly. After all, cold water plunges were once used as a form of torture and punishment. As more people experiment with adding cold hydrotherapy into their health and fitness routines, experts warn that it should be more widely recognized as a potentially lethal activity.
Sixty percent of deaths in cold water happen in the first minute of immersion. Medical experts have reported deaths triggered by cold water immersion therapy, even in controlled settings.
Both the American Heart Association and the British Heart Foundation have warned about the risks of cold therapy, saying it should be practiced with caution and thoughtfulness.
Exposing your body to very cold water can lead to shock, which can cause an increased hart rate, higher blood pressure, and shortness of breath. Athletes who push themselves in their cold hydrotherapy practices run the risk of hypothermia and elevated stress hormone levels, which can increase the risk of abnormal heart rhythms and other negative effects.
What's the Bottom Line?
Despite all the popularity and hype, there's little scientific evidence to support the health benefits of cold plunges or cold hydrotherapy. Most evidence is anecdotal at the moment, but scientists are eager to conduct more studies.
Feel free to follow your own inclinations. If this is a practice you find beneficial and you feel confident in the overall benefits vs. risks, then by all means continue, but with caution.
If this is not something you have experimented with, proceed with caution! There is still much to learn about the practice. Chat with your healthcare provider before experimenting and take precautions. Many experts warn that cold therapy should never be practiced alone–even in your own home.
For endurance athletes, while we do understand the anti-inflammatory benefits of ice and cold therapy on injuries, every athlete is different. One size does not fit all and cold therapy is another example of that. What's good for Lucy Charles-Barcley may not be good for everyone else.