The Shocking Benefits of Cold Showers

Many studies explore the benefits of hydrotherapy and water temperatures. While hot showers can provide relief from respiratory symptoms and provide muscle relaxation, cold showers also have benefits. Applying ice packs and taking cold water showers leads to physiological reactions, such as decreased muscle spasms, reduced edema, and lower metabolic function.

Although comfortable showering temperatures are a matter of preference, some health professionals say the best temperature for bathing is around 112 F. Researchers exploring the benefits of cold showers subjected participants to water that was around 70 F. This is a similar temperature to the water that flows directly from residential plumbing into showers, bathtubs, and sinks at the lowest setting.

A 2012 study showed that cold-water immersion reduces soreness and inflammation and constricts blood vessels after an intensive workout. In 2017, researchers found no evidence of faster functional recovery and improved performance among athletes using cold-water immersion therapies. However, this hydrotherapy reduces muscle soreness and possesses analgesic and placebo-like properties.

Studies show that exposure to cold activates the sympathetic nervous system, which regulates heart rate, blood pressure, and other functions. This increases the level of endorphins in the bloodstream. Because the skin has a high density of cold receptors, taking a cold shower sends a higher number of electrical impulses from the peripheral nerve endings to the brain and can produce an anti-depressive effect.

Several types of body fat exist in the human body. Brown fat, or brown adipose tissue, burns calories to generate heat in the body. It also increases blood flow and leads to a higher metabolism in the tissues, increasing their fat-burning capabilities. Researchers say additional studies are necessary to determine how well cold showers trigger this reaction and how effectively the reaction burns fat.

In 2016, a study found that routinely showering in cold water resulted in a 29% reduction of sick leave from work, although it did not shorten the length of the illness. Participants who combined cold showers with regular physical activity experienced a 54% reduction in the number of sick days taken off from work.

A Swiss study found that taking nine-minute warm showers, six times each week produces up to 248 kilograms of CO2 per person each year, the same amount of CO2 that a flight from Zurich to Paris and back produces. Researchers surmised that in homes using natural gas, cold showers could reduce greenhouse emissions by 19%, providing an additional long-term health benefit.

Researchers who conducted a 2016 study said the first 30 seconds of a cold shower produce the greatest physiological response. Duration of the shower did not affect how participants felt afterward. Cold shower proponents suggest starting with warm water, then slowly increasing the cold water every 10 seconds to reach the desired temperature. The positive effects reach a peak after a three-minute cold shower.

A 1991 study found that cold water does not increase testosterone concentrations in serum, but exercise does. They compared two groups of 19-year-old men, one exercising for 20 minutes and another receiving cold water stimulation. The group that exercised experienced significant testosterone level increases of just under 21%, while the group exposed to the cold water experienced decreases of 10%.

Showering causes breathing issues for some people who have chronic obstructive pulmonary disease (COPD), especially if the water is extremely hot or cold. Before adopting a cold shower routine, individuals with COPD should consult with their physician. People with weaker immune systems or heart failure should avoid cold showers due to the potential for an initial shock that results in sudden changes in body temperature and heart rate.