(optics) The principle that if a beam of light is reflected back on itself, it will traverse the same path or paths as it did before reversal.
(statistical mechanics) microscopic reversibility
A basic training principle that there is a gradual loss of training effects when the intensity, duration, or frequency of training is reduced. See also detraining effects.
A basic principle of training that refers to the gradual loss of beneficial training effects when the intensity, duration, or frequency of training is reduced. Training effects produced over a short term are usually lost more quickly than those produced over a longer term, and strength losses tend to be faster than mobility losses.