Charley horse is a colloquial term typically used to refer to a muscle cramp or stiffness, particularly those of the calf, foot, leg, or more rarely, the arm. Some may use the term interchangeably with the term dead leg or thigh contusion, referring to a contusion caused by a physical blow to the leg or thigh.
The term came into use in the setting of baseball in the United States in the 1880s, though its exact origin is uncertain.
In sports therapy, an ice bath, or sometimes cold-water immersion, Cold plunge 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.
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 has been mixed, 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.