In sports therapy, an ice bath, or sometimes cold-water immersion or cold therapy, is a training regimen usually following a period of intense exercise in which a substantial part of a human body is immersed in a bath of ice or ice-water for a limited duration. While it is becoming increasingly popular and accepted among athletes in a variety of sports, the method is controversial, with a risk of hypothermia, with the possibility of shock leading to sudden death. Many athletes have used cold water immersion after an intense exercise workout in the belief that it speeds up bodily recovery; however, the internal physical processes are not well understood and remain elusive. Evidence supporting cold water immersion as part of an athletic training regimen remains inconclusive, with some studies suggesting a mild benefit such as reducing muscle damage and discomfort and alleviating delayed onset muscle soreness, with other studies suggesting that cold water immersion may slow muscle growth and interfere with an overall training regimen. Techniques Bath It is done by standing or sitting in a bucket or bath of icy water. One writer advised: "don't overdo it." Wearing rubberized "dive booties" on the feet (to protect toes) as well as rubber briefs to warm the midsection have been recommended. Champion weightlifter Karyn Marshall, who won the world women's weightlifting championship in 1987, described what it was like to take an ice bath after a day of competition at the CrossFit Games in 2011 in Los Angeles: One report suggested that if ice water is circulating, it's even colder such that the water will be colder than measured by a thermometer, and that athletes should avoid overexposure. Physical therapist Nikki Kimball explained a way to make the bath more endurable: Ice bath only versus contrast bath therapy Some athletes use a technique known as contrast water therapy or contrast bath therapy, in which cold water and warmer water are alternated. One method of doing this was to have two tubs––one cold (10–15 degrees Celsius) and another hot (37–40 degrees Celsius) ––and to do one minute in the cold tub followed by two minutes in a hot tub, and to repeat this procedure three times. Temperature and timing The temperature can vary, but is usually in the range of 50–59 degrees Fahrenheit or between 10 and 15 degrees Celsius. Some athletes wear booties to keep their toes warm or rubberized coverings