Recovery (Contrast)

Contrast therapy may increase your resilience to stress. Cold water immersion causes a stress response that evolved millions of years ago to help us cope with a wide range of potential threats. Each time you repeat the practice the stress response is reduced.

This ability to adapt to stress can have amazing benefits when faced with other stresses through a process known as “cross adaptation”. A mechanism whereby one form of stress adapts the body for another. In addition, heat shock stress proteins are synthesized when cells are exposed to a wide variety of physiologic stresses. 

The stress response is evolutionarily highly conserved, suggestive of an essential function(s) for the survival of organisms, protecting them from harmful trauma. Exposure to cold is also known to activate the sympathetic nervous system and increase the levels of the stress-reducing hormone beta-endorphin 

Cold water swimming has been shown to have profound positive effects on mood, anxiety and even depression. Some studies have also reported that contrast therapy increases brain chemicals that regulate mood, such as dopamine, following a cold soak, which may explain the post-swim “high” people feel.

Additionally, due to the high density of cold receptors in the skin, a cold plunge may send an overwhelming amount of electrical impulses from peripheral nerve endings to the brain, which could result in an anti-depressive effect.

Athletes might find that contrast therapy helps alleviate post-game fatigue. A 2017 meta-analysis of the research found that contrasting hot and cold baths helped team sports players recover from fatigue 24-48 hours after the game.

Researchers also measured both delayed onset muscle soreness and muscle weakness in elite athletes following strenuous workouts and found that contrast bath therapy improved both the soreness and weakness better than passive resting alone.

Another Study conducted in 2007 showed that contrast bath therapy can also help decrease the lactic acid in your body, helping you recover from the soreness and fatigue of strenuous exercise.

There is some evidence that contrast baths reduce swelling. In a 2016 study involving 115 people with ankle sprains, contrast hydrotherapy lessened swelling around 3 days post-injury.

Other studies have suggested that daily exposure to cold water could, over a period of weeks or months, boost anti-tumor immunity.

Small studies have found that brief immersions (5 minutes) in water less than 59°F (15°C) can even help to increase metabolism.