effect appears even after a relatively small number of contractions, possibly as few as two. In one study, a first bout of 10, 20 or 50 contractions provided equal protection for a second bout of 50 contractions three weeks later. The reason for the protective effect is not yet understood. A number of possible mechanisms, which may complement one another, have been proposed. These include neural adaptations (improved use and control of the muscle by the nervous system), mechanical adaptations (increased muscle stiffness or muscle support tissue), and cellular adaptations (adaptation to inflammatory response and increased protein synthesis, among others). Prevention Delayed onset muscle soreness can be reduced or prevented by gradually increasing the intensity of a new exercise program, thereby taking advantage of the repeated-bout effect. Soreness can theoretically be avoided by limiting exercise to concentric and isometric contractions, but eccentric contractions in some muscles are normally unavoidable during exercise, especially when muscles are fatigued. Limiting the length of eccentric muscle extensions during exercise may afford some protection against soreness, but this may also not be practical depending on the mode of exercise. Static stretching or warming up the muscles before or after exercise does not prevent soreness, although there is evidence that whole body vibration therapy performed before exercise may lessen both the soreness and reduced range of motion caused by delayed onset muscle soreness. Other preventative measures with evidence of efficacy based on randomized controlled trials include consumption of saffron. Wearing compression garments has not been demonstrated to have a significant effect on delayed onset muscle soreness. Treatment The soreness usually disappears within about 72 hours after appearing. If treatment is desired, any measure that increases blood flow to the muscle, such as low-intensity activity, massage, nerve mobilization, hot baths, or a sauna visit may help somewhat. Immersion in cool or icy water, an occasionally recommended remedy, was found to be ineffective in alleviating DOMS in one 2011 study, but effective in another. There is also insufficient evidence to determine whether whole-body cryotherapy – compared with passive rest or no whole-body cryotherapy – reduces DOMS, or improves subjective recovery, after exercise. Counterintuitively, continued exercise may temporarily suppress the soreness. Exercise increases pain thresholds and pain tolerance. This effect, called exercise-induced analgesia, is known to occur in endurance training (running, cycling, swimming), but little is known about whether it also occurs in resistance training. There are claims in