Does a cold plunge have health benefits?

You’ve probably seen athletes sitting a tub of ice water after a competition. This practice of cold-water immersion — also known as a cold plunge, cold therapy or ice bath — has gained popularity as part of a wellness routine for exercise recovery and stress relief.

A cold plunge is any type of cold-water immersion. It can include a tub full of cold water and ice cubes, a “polar bear swim” in a freezing lake or a cryochamber at a healthcare facility.

Cold water plunging isn’t new. It's been around since ancient times.

While some health benefits of cold plunging are not well understood, others have shown to be effective when the cold plunge is done safely. Read on to learn about the benefits and risks, as well as how you can try cold plunging yourself.

Research-based cold plunge benefits

There are three main proven health benefits of cold-water plunges:

• Enhanced performance following physical endurance activities like distance running, a football game or a tennis match
• Better memory function and mood improvements
• Increase in metabolism

An ice bath or cold plunge may help with muscle recovery

Endurance exercise can cause muscle damage, leading to inflammation and muscle soreness. Applying cold packs or submerging the affected parts of your body in cold water within a couple of hours may slow down the inflammation process by narrowing blood vessels and slowing blood flow. This may delay the onset of muscle soreness and even repair damaged muscle fibers.

A cold plunge can increase metabolism and help you lose weight

Your body contains brown fat, a type of fact that acts as your body’s furnace. When you’re exposed to cold, you shiver to generate extra heat, and you burn more of this brown fat and calories, which speeds up your metabolism as your body works to warm you back up.

Brown fat is a major fuel in the body during aerobic activity. When you are immersed in water, your heart rate and your energy output will increase. Calories are units of energy, so you’re going to burn more calories.

A cold plunge or ice bath may help you regulate your blood sugar levels

Because a cold plunge may increase your metabolism, over time, it can help regulate your blood sugar levels more effectively.

Additionally, some research has shown that when you shiver, your muscles react in a similar way as when you exercise.

However, an ice bath is not a replacement for exercise and a healthy, balanced diet.

Cold plunges may improve mood and decrease symptoms of depression or anxiety

Immersing your body in really cold water causes a release of dopamine and norepinephrine. These are chemical messengers in your brain and body that regulate your mood, focus and physical function.

A cold plunge may boost your immune system

Some research suggests that cold water immersion may stimulate white blood cell production, which can boost your immune system and may decrease your likelihood of becoming ill. Several studies suggest that people who participate in cold water plunges take fewer sick days from work.

But more research is needed to investigate this further.

Cold plunge risks

For starters, cold therapy is uncomfortable for many people. It can also pose risks to some people with preexisting conditions like high blood pressure and heart disease. It can be dangerous if the temperature is too cold or if you are in a large body of moving water like a lake, river or ocean.

The ambient human body temperature is around 91 to 95 degrees Fahrenheit, but now we're talking now 50 to 60 degrees Fahrenheit.

Cold water immersion also is not a good idea after resistance training or weightlifting. That’s because ice baths can interfere with the process by which your muscles become bigger and stronger.

Hypothermia

Staying submerged in cold water for more than a few minutes can lead to hypothermia and even put you at risk for frostbite. So, make sure you have towels and clothes nearby to warm up afterward.

Cardiovascular shock

Also known as heartrate shock, this can affect people with underlying conditions like heart disease or high blood pressure.

A cold plunge can put stress on your cardiovascular system – all of a sudden you're pushing your heart rate up to warm you up. It can make you feel like you’re gasping for air. It can trigger an irregular heartbeat, known as arrhythmia.

This shock can impair your thinking — which is even more dangerous when you’re submerged in water.

Who should avoid a cold plunge?

If you have high blood pressure or heart disease, speak with your doctor before trying a cold plunge. That’s because excessive cold can raise blood pressure or worsen other heart issues.

You should also avoid an ice bath if you have breathing issues, such as asthma. An asthma episode can also strain your heart, lungs and blood vessels. This can lead to cold shock, involuntary gasping reflexes and hyperventilation.

How to try cold therapy like a cold plunge

First, don’t attempt a cold plunge if the water is colder than 50 degrees Fahrenheit. Any colder could put you at risk for hypothermia.

Make sure you have some kind of device to monitor the temperature.

The key is to start out slowly, for no more than 30 seconds at a time, and in water that’s not too cold. First immerse your arm or leg before going further. If your body handles it well, you can begin to increase the time you’re immersed in water, up to no more than three to five minutes at a time.

You can repeat the immersion within the same day, but take breaks between cold plunges. That might look like 30 seconds in the water, followed by a two-minute break and another 30 seconds, or you might try plunges on consecutive days.

You can increase how long you’re in the water as you grow comfortable with cold plunging.

You can work your way up to a combined 11 or 12 minutes per week.

I recommend cold-plunging in controlled environments like a bathtub rather than uncontrolled ones like a body of water with a current or waves. With a tub, you can get out fast if you need to. You can also try it in a lake if it’s safe and you are able to remove yourself quickly from the water if it becomes necessary.

Make sure you keep your head above water, which can also increase the risk for cold shock, hypothermia and drowning.

Afterward, warm up right away by drying off with a towel and dressing in warm clothing so your body can recover.

Carol Harrison is a senior exercise physiologist at UT MD Anderson.

Request an appointment at UT MD Anderson online or call 1-877-632-6789.