Is Cold Water Swimming Good for You?

According to Diwadkar, while science has long focused on the destructive nature of stress, more emerging research shows that willfully stressing your mind and body in a controlled way helps train your system to better handle stress. He believes exposure to controlled stress releases neurochemicals in the brain that may be beneficial.

This response is similar to a "runner's high." This process, known as hormesis, is empowering, boosts confidence and mood, and with practice, it may translate to stress management in daily life. 

https://health.usnews.com/health-news/blogs/eat-run/articles/is-cold-water-swimming-good-for-me