Are Ice Baths Really Beneficial? The Cold Therapy Debate

Is “cold therapy” really as effective as its enthusiasts claim? While some athletes and ice bath fans swear by cold plunges as a cure-all for anxiety, sore muscles, and weight loss, health experts have differing opinions on whether ice baths are beneficial on all fronts. 

What Is Cold Therapy? 

It goes by many names — cold water immersions, (CWI), cold therapy, or cryotherapy — but it all comes down to lowering yourself into a vat of frigid water. Ice baths are often used by athletes recovering from intense training to relieve sore muscles, and generally involve submerging the body in 55-60 degree water for 10-15 minutes. That may not sound so cold, but it’s certainly enough to take your breath away. 

What Are the Benefits?

Some of the purported benefits of ice baths have more evidence to back them up than others — especially their ability to reduce swelling after intense bouts of exercise. 

Lowering Core Body Temperature

Quite simply, cold water cools the body down. After working out in high temperatures, a dip into an ice bath can feel pretty good, and lowers one’s core body temperature that rises during intense activity. 

Reduced Swelling

During an ice bath, blood vessels in immersed areas constrict (a phenomenon called “vasoconstriction”), meaning that blood doesn’t flow as quickly. This helps to temporarily reduce inflammation and relieve pain. After removing the body from ice water, the blood vessels expand again as the body heats back up, allowing the blood to flow back into tissues and remove waste products like lactic acid that build up during physical activity. Furthermore, our perception of pain is also impacted by this process, as our nerve conduction velocity slows during cold water exposure.

While studies have produced various results about the efficacy of ice baths, a 2022 study showed that cold water immersion benefited athletes recovering from intense bouts of exercise. During strenuous workouts, small tears form in muscle fibers, and ice water can prevent further damage to these areas. Swelling can also hinder performance and cause soreness, but ice baths can reduce that inflammation and allow athletes to train the following day without experiencing as much soreness and pain. 

Mental Benefits

Proponents of ice baths often cite improved mental health as a result of their immersions. The popular Wim Hof Method of meditation combines cold immersion with breathing techniques, and a recent observational study found reduced stress responses in participants. While Wim Hof’s method also entails breathing exercises that likely contribute to these improved mental outcomes, ice baths alone can invoke positive personal responses. Many people experience feelings of clarity while immersed, and the soothing effect of cold water can help with relaxation, especially after a workout. Some find that immersions make them feel more resilient to discomfort and stressors, which in turn help them handle other difficult situations in their lives.

Some proponents of cold therapy claim that it can combat depression, but relatively limited research points to decreased states of anxiety during immersions. An older study found that submerging the body in cold water increased concentrations of dopamine by 250%. This relief could be due in part to the stimulation of the vagus nerve: a nerve associated with the parasympathetic nervous system that runs from your brain to your abdomen. When blood vessels restrict, the nerve is activated and helps to slow heart rate and lower blood pressure — all things that can help the body relax. However, this can be accomplished in ways other than plunging your body into ice water, such as a cold compress to the neck. Additionally, cold water triggers the release of the stress hormones noradrenaline and cortisol.

Ultimately, there hasn’t been conclusive research on whether cold water immersion alone improves mental health, but the positive personal experiences of users point to its real benefits for some. 

What’s the Debate?

The science behind all of the lauded benefits of ice baths, unfortunately, is unbalanced. More research is needed to conclusively determine the legitimacy of outcomes. 

Recovery

Gabe Mirkin — who coined the term RICE (rest, ice, compression, elevation) — released a statement in 2015 about how ice might actually delay recovery and healing. A 2019 study found that legs chilling in ice baths after strenuous exercise were less capable of muscle-protein synthesis afterward, and other research has indicated that some cells and proteins that regulate muscle growth post-exercise have reduced activity after cold water baths. Reduced blood flow also reduces the amino acids going to muscles, which are important for recovery and growth. So, while cold plunges might benefit athletes and others suffering from inflammation in the short-term, they might not be helpful for long-term performance, and might even hamper progress. 

Mental Health 

The meditative benefits from breathing and focus during cold plunges certainly work for some users, but there is little clinical evidence to support its long-term effects on mental health. Ice baths are sometimes touted as a replacement for mental health treatment, which many mental health professionals warn against. Ultimately, without further research, cold water immersions shouldn’t be viewed as “cures” for anxiety and depression. 

Heart Health

Ice water immersions can be very harmful to those with heart issues, like high blood pressure or cardiovascular disease. Plunging in cold water triggers a “cold shock response” — rapid increases in breathing, blood pressure, and heart rate — which puts more stress on the heart, according to the American Heart Association. This can cause hyperventilation, or even lead to arrhythmias and heart attacks.

Hypothermia Risk

Even after raising your core temperature significantly during exercise, staying in the water too long can cool you down too much — remember, water takes heat away from the body 25x faster than the air. In the cold, blood leaves the extremities to protect the organs, leaving arms and legs without good circulation, which can impact coordination when trying to stay afloat in a body of water. People with diabetes should be especially cautious, since the condition often reduces the body’s ability to maintain a core temperature.

Weight Loss

Weight loss is often listed as a benefit of cold therapy, but the research is lukewarm. Because the body uses calories to stay warm, cold water immersions might burn a very small amount of calories. Cold plunges also increase a hormone called adiponectin that prevents resistance to insulin. This increase could improve the way insulin works in the body, which in turn might help reduce the risk of developing diabetes. However, experts note that we still don’t know enough to draw decisive conclusions about CWI’s weight loss benefits. 

Immune System

Wim Hof cites immune system improvements as a result of his cold water immersions paired with meditative breathing techniques. There is some evidence that cold immersion stimulates white blood cells that fight infections in the body, and one oft-cited 2016 study in the Netherlands found a reduction in absence from work due to sickness after participants incorporated cold showers into their routine. But again, there is not enough evidence to definitively claim that immune system improvements are a clear benefit of cold therapy on its own. 

How Can You Take an Ice Bath Safely?

1. Check with your doctor before taking the plunge. Mention any preexisting conditions to determine whether cold water immersions are safe for you. 
2. Consider joining a group. The cold might shock you, especially on your first go around. If you’re going in an outdoor area rather than at home, it’s much safer to try plunging with others around.
3. Plan your timing. Cold water immersions are most beneficial right after exercising, so get into the bath after a workout as soon as you can.
4. Pay attention to temperature. Fill the tub with a 1:3 ratio of water to ice. Use a thermometer to gauge temperature until it reaches 55-60 degrees. Add ice and/or warm water as needed. 
5. Go slow. Lower yourself in slowly and carefully, Start small (30 seconds to a minute) then gradually add time. Never stay in the water longer than 15 minutes. 
6. Try other methods. If you aren’t privy to a full ice bath, try cold showers, building up your time in the same way.

The Takeaway

Personal experiences with ice baths vary, and some participants may experience benefits. If cold therapy works for you, keep practicing it safely. However, further research is needed to conclusively state whether cold plunges have a decisively positive impact on mental and physical health.