The Science Behind Ice Baths and What They Do (2024)

Ice baths are thought to boost the immune system, reduce stress, and even burn calories. Some studies suggest that cold water immersion can help with chronic inflammation, and may improve cholesterol levels and insulin sensitivity. However, some of these effects may be influenced by other factors, like a healthy lifestyle or positive mindset.

As for how long you should stay in an ice bath, most experts recommend no more than 10 to 15 minutes. Staying too long in cold water can actually be harmful, especially if you have a history of heart or circulatory problems. More research is needed to fully understand the safety and benefits of ice baths.

The Science Behind Ice Baths

Ice baths are thought to affect several body processes. Here's what they do:

• Entering the ice bath: Within seconds of entering the ice bath, the "cold shock response" kicks in, causing your blood vessels to constrict and stress hormones to surge. This can lead to a rapid increase in breathing, heart rate, and blood pressure.
• Blood flow changes: Constricted blood vessels reduce blood flow, limiting swelling, inflammation, and pain. The cold also slows metabolic processes that break tissues down, and supports recovery from micro-tears in muscles.
• Post-ice bath: When blood flow is reduced, waste products like lactic acid can build up in the muscles. As the body warms up, blood flow returns to normal, helping to clear out these waste products, support muscle recovery, and reduce soreness.

Ice baths are most commonly used for workout recovery and inflammation reduction, but researchers are also exploring their potential benefits for other uses. Ongoing studies continue to investigate the science of ice baths and how they may impact healing.

Are Ice Baths Actually Good for You?

An ice bath reduces core body and tissue temperature. Everyone reacts differently, but there are several ways ice baths may be beneficial. Research suggests they may:

• Relieve post-workout muscle pain: Some studies show that cold water immersion within an hour of exercise can reduce pain and help with recovery for up to 24 hours. Results are mixed, though, with some evidence suggesting ice baths might reduce muscle mass and strength gains over time.
• Ease swelling and inflammation: There's a good reason we reach for an ice pack after an injury. The same narrowing of blood vessels that eases pain also helps reduce swelling and inflammation.
• Prevent overheating: Hyperthermia, when your body temperature is dangerously high, is common in athletes. Cold water immersion can help lower your temperature and reduce the risk of heat stroke. Studies show that immersion in cold water (about 50°F or 10°C) cools you down twice as fast as passive recovery.
• Manage weight: Cold temperatures initially lower metabolism. But then it takes extra calories to warm back up. The cold may also help turn white fat cells into brown fat cells, which may make heat and help control blood sugar and insulin levels. This may help with weight management.
• Improve mood: Research suggests cold water immersion can improve mood. One study found that 20 minutes in 55°F (13°C) seawater led to an immediate mood boost, with even 18 minutes showing significant improvement. Other studies also show increased alertness and reduced nervousness after cold immersion.
• Soothe the skin: Cold causes small arteries and veins in the skin to constrict. This might help ease inflamed or itchy skin. Avoid taking an ice bath if you have open wounds.
• Boost immune health: Cold water immersion may improve stress response and lower the risk of respiratory infections. One study found that alternating hot and cold showers for 30 days led to fewer sick days in adults with severe health conditions. More research is needed to confirm and understand this effect.
• Improve insulin sensitivity: Studies show that repeated cold-water immersion can boost insulin sensitivity and lower insulin levels by increasing adiponectin production, a protein that plays a key role in preventing diabetes.

All together, there's no scientific consensus on the benefits of ice baths. Some researchers believe many studies are biased or not well-designed. Problems with the studies include:

• Small groups of participants
• Different ways of doing ice baths
• Inconsistent ice bath temperatures
• Focusing only on young, healthy athletes or only one gender
• Relying on people’s personal or anecdotal reports

More well-designed studies are needed to confirm whether ice baths are really beneficial.

How Long It Should Last

There are no official recommendations for how long to take an ice bath. Most experts suggest spending up to 10 to 15 minutes in the cold water. You can do this a few times a week or every day. If you're doing it for your muscles, try to bathe within an hour of your workout.

According to the American Heart Association, the most dangerous time in an ice bath is the first 10 seconds to a minute. Likewise, the National Center for Cold Water Safety warns that sudden immersion in water under 60 degrees can kill a person in less than a minute.

Gradually adjusting to cold water is as important as timing your ice bath. If you're new to ice baths, start with cold showers and slowly progress to colder baths for longer durations. Experts also suggest putting cold water on the back of the neck before submerging into the ice bath. This can prime your neurological system for the cold shock to come.

How to Draw an Ice Bath

To draw an ice bath:

• Use a thermometer to test the water and ensure it's not too cold.
• Aim for water temperature between 50°F and 59°F. You can use cold tap water and add ice.
• Keep a large towel close by so you can wrap up quickly when you get out.
• Wear light clothing to protect your skin and sensitive areas.
• Set a timer for 10 minutes so you don't stay in too long.
• If this is your first time, go in up to your waist. Over time, you can gradually lower yourself until the water reaches your neck. Never submerge your head. Cold shock can cause you to gasp and inhale water, which can result in drowning.
• Try to relax and wait for the timer. But do get out early if it doesn't feel right.
• When the timer goes off, get out, remove your wet clothes, and towel dry immediately.

Consider having someone on standby until you're safely out of the tub and warmed up.

Side Effects

Ice baths have some disadvantages. Potential side effects include:

• Low body temperature (hypothermia)
• Nerve damage
• Ice burn on your skin
• Cold shock response, which increases respiratory rate, heart rate, and blood pressure
  

Who Shouldn't Use Them

Serious risks may depend on age, health, water temperature, and the length of time you're in the bath. You may be at risk of complications if you have:

• Poor circulation
• An open wound
• Diabetes
• Heart disease
• Neuropathies (nerve damage)
• Raynaud's syndrome, when your fingers and toes turn blue and/or white in the cold
• Cold urticaria, a condition in which you get hives in response to cold

Additionally, ice baths may not be safe for:

• Children and teens: Children's bodies cannot handle temperature changes as well as adults. Parents should consult a healthcare provider before allowing their child to take an ice bath. Children and teens should not take an ice bath without supervision.
• Older adults: Older adults may have health issues or poor circulation, which can increase the risk of dangerous side effects from ice baths.
• People taking certain medications: Some medications, like beta-blockers, blood thinners, and blood pressure-lowering drugs, can affect how the body handles temperature changes.

If you fall under any of these categories, it's very important to consult a healthcare provider before starting ice baths to ensure they are safe for you.

Summary

There are several potential benefits to taking an ice bath. It may help relieve achy muscles after a workout or ease inflammation. It might even put you in better spirits. But studies have produced mixed results and there's a need for more research.

Potential side effects include ice burn and low body temperature. And there may be a risk of complications if you have a health condition such as diabetes or nerve damage. It's best to check with a healthcare provider to learn if ice baths are safe for you.