Cold Water Therapy: What to Know
Medically reviewed by Amy Kwan, PT
Cold water therapy, also known as cold immersion therapy, is voluntary exposure to cold water for its potential health or exercise recovery benefits. And it's certainly not a new concept: papyrus from ancient Egypt and writings by the ancient physician Hippocrates of ancient Greece describe the use of cold water therapy for medicinal purposes.
Cold plunges, cold showers, ice baths, and winter swimming are all types of cold water therapy. There are several reported benefits, including improved circulation, fat-burning, and mood benefits. However, research on cold water therapy has not definitively proved this. This article will review the potential benefits of cold water therapy and how to perform cold water therapy at home.
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What Are the Benefits of Cold Water Therapy?
Exposure of the body to cold water causes several responses in the body that may ultimately explain its benefits. One explanation is that cold water therapy exposure activates adaptive responses in the body, a phenomenon known as hormesis.
But what happens when the body is exposed to cold and how can this benefit someone? When you get into an ice bath you may notice goosebumps and shivering. These are responses that help generate heat. Further, blood vessels on the surface of the skin constrict so that blood is directed toward the internal organs to limit heat loss.
The body also increases heat production through the activation of brown fat, a type of adipose tissue that can create heat. With cold water immersion specifically, the body also experiences reflexes that affect the nervous system, respiration, heart rate, and blood pressure.
There are several reported health and wellness benefits of cold water therapy. These include the following, and the research behind them is discussed in the sections below.
Reduction of muscle soreness and inflammation
Accelerated recovery after intense exercise or physical activity
Improved immune system function
Potential stress reduction and mental health benefits
Promotion of fat-burning and weight loss
Improved circulation
Less Muscle Soreness
Many athletes perform cold water immersion to improve recovery after exercise. The vasoconstriction, decreased nerve conduction, and reduced inflammation that occurs with cold water therapy may be responsible for these effects.
A 2022 systematic review suggests that athletes who performed cold water immersion after high-intensity exercise experienced less muscle soreness and improved recovery and power. However, these benefits were not all seen after eccentric (strength-building) exercise.
Faster Cooldown if You’re Overheated
Exercise can cause the body to overheat. This is a serious condition known as heatstroke. This is a risk particularly when exercising outdoors in hot or humid climates. Cold water therapy can lower the elevated body temperature faster.
A 2016 review found that participants with hyperthermia (elevated body temperature) who performed cold water immersion recovered body temperature twice as fast compared to those who did not; they recommend immersing the limbs and torso in water at a temperature of 50 degrees or lower.
May Ease Depression Symptoms
Some studies suggest that cold water therapy has beneficial effects on mood and might lower stress and help manage depression symptoms. One study in a group of young adults showed that performing chest-deep cold water immersion just once resulted in improved mood scores and energy 20 minutes later compared to those who did not.
Another study looked at mood as well as brain waves following cold water immersion and also found improved mood with changes in brain connectivity of specific brain networks involved in emotion, self-regulation, and attention.
May Boost the Immune System
Research suggests that cold water therapy may boost the immune system. Regular exposure to cold water therapy can increase certain immune cells and proteins that help the body fight off infections. One study showed that people who took hot-to-cold showers (starting with hot water and ending with cold water) for a month reported feeling sick for fewer days when questioned three months later.
Can Cold Water Therapy Help With Weight Loss?
The idea that cold water therapy can help with weight loss stems from the activation of brown fat that occurs with exposure to cold. Most of the fat in our bodies is white fat whose purpose is to store energy. Brown fat is a type of adipose, or fatty tissue in the body. This tissue breaks down fatty acids and triglycerides to release heat. Cold water immersion activates brown fat, but there is a lack of research on its effects on weight loss.
How Is Cold Water Therapy Performed?
There are several types of cold water therapy, and you can tailor cold water therapy to your own preferences. You can perform cold water therapy at home or at the gym, spa, or wellness studio.
Cold showers can be performed at home easily. And you don't need to spend the entire shower in cold water. You can jump into a cold shower or start warm and slowly turn to cold. Even just ending the shower with 30 to 90 seconds on the coldest water setting may have beneficial effects on mood and energy.
Cold water immersion typically involves placing the torso and/or limbs in cold water, such as an ice bath. Protocols in research vary in terms of temperature, length of time, and amount of immersion of the body. According to one review, you can add ice to water to aim for a temperature between 50 and 59 degrees for 11 to 15 minutes. Avoid having the water too cold, which can have negative effects. Do not stay in cold water for too long as it can cause hypothermia and tissue injury.
Winter swimming, also known as ice swimming, is another type of cold water immersion popular in some northern countries like Finland and Poland. There are dangers to this recreational activity, and those without experience should not attempt it without professional support.
Safety Considerations and Precautions
There are several safety considerations to take into account when considering cold water therapy. With immersion in cold water, our bodies have physiologic responses and reflexes that are out of our control. These can cause arrhythmias and a loss of consciousness, resulting in drowning.
The risks of cold water immersion include the following:
Hypothermia is defined as a body temperature of less than 95 degrees. At lower-than-normal body temperatures, you may experience confusion, drowsiness, and fatigue.
Circulatory problems: Those with Raynaud's or peripheral artery disease can have abnormal responses to temperature and experience tissue and nerve damage.
Arrhythmia and cardiac arrest: At cold temperatures, our heart rate normally slows down. If it slows down too much, the heart can't pump enough blood to the body, resulting in a loss of consciousness (fainting). If someone faints in water, they can drown. Furthermore, some people are at risk of ventricular arrhythmias with exposure to cold water. This can lead to cardiac arrest, which stops the heart from pumping blood to the body and can result in death. When performing cold water immersion (particularly to levels above the limbs), having someone nearby to supervise you is best.
Drowning: In addition to the risk of the heart rhythm problems noted above, drowning can happen due to the inability to suppress the hyperventilation that occurs as part of the cold shock reflex. Water that is too cold can also impair your muscle function, making it hard to stay afloat.
Tips and Best Practices
If you're interested in starting cold water therapy, there are some things to consider about acclimation, timing, and safety.
When starting cold water immersion therapy, let yourself acclimate. Start with warmer temperatures for a few minutes. Over time, you can aim for longer sittings (11 to 15 minutes) at lower temperatures but not lower than 50 to 59 degrees).
If performing cold water therapy for athletic recovery and muscle soreness prevention, the best timing is right after a vigorous exercise session.
There isn't a consensus on how frequently cold water therapy sessions should be done to get the most beneficial results. Some studies suggest more benefits result only when they're performed after very intense exercise (such as athletic training or tournaments).
Talk to Your Provider First
Talking with a healthcare provider before attempting cold water therapy on your own is best given the potential risks involved. This is particularly true for older adults, people with certain health conditions like heart disease, or people who take medication.
Heart disease
Neurologic conditions
Peripheral artery disease
Discuss any underlying conditions for which you may be at an increased risk.
Have an Observer With You
Having an observer present during cold water therapy is very important. This is due to the risk of drowning and the potential need for assistance. Firstly, immersion in cold water causes physiologic reflexes out of our control that may impair our breathing or lead to loss of consciousness. Cold water can also affect mentation and muscle control, making it hard to get out.
Limit Immersion
Swimming in colder water for too long can cause your core body temperature to become dangerously low, a condition known as hypothermia. This can happen when swimming for longer periods, even in water that is not ice cold. If you're starting out, limit your time to a couple of minutes (supervised) and work your way up. Don't stay in an ice bath for more than 15 minutes.
How to Warm Up When You Get Out
Cold water therapy can lower your body's core temperature and result in hypothermia. The benefits of cold water therapy are related to the amount of time spent in cold water (around 10 to 15 minutes). Beyond that, there doesn't appear to be much benefit, but the risks go up the longer you spend cold, so it's important to warm yourself up afterward. Have a towel ready so you can dry off and get dressed as soon as possible afterward. Consider drinking a warm beverage to help warm up.
Summary
Cold water therapy, which includes ice baths, cold showers, and cold water swimming, is commonly performed by athletes for physical recovery. Studies suggest it may also have wider-ranging benefits for the immune system and mood. Cold water therapy can be performed simply and informally at home with cold showers, whereas cold water immersion (ice baths or ice plunges) can be done under the supervision of a physical therapist or at a wellness spa.
Read the original article on Verywell Health.
