Eccentric training
（重定向自Eccentric exercise）
An eccentric contraction is the motion of an active muscle while it is lengthening under load. Eccentric training is repetitively doing eccentric muscle contractions. For example, in a biceps curl the action of lowering the dumbbell back down from the lift is the eccentric phase of that exercise — as long as the dumbbell is lowered slowly rather than letting it drop (i.e., the biceps are in a state of contraction to control the rate of descent of the dumbbell).