Proper recovery should allow the body to repair muscle and connective tissue broken down during training as well as restore energy stores that have been depleted. In addition, adequate recovery will permit full restoration and increase energy producing enzymes in muscles. The result is a bigger, stronger, and more fit athlete. The amount of rest necessary between sets varies depending on the type of exercises being performed, the individual performing it and the goal of the training program. The rest interval between sets allows for the recovery of the anaerobic energy systems and determines what amount of the lactic acid produced during exercise will be removed.
Lactic acid build up in muscles inhibits muscle contractions.
For this reason, athletes normally should utilize rest intervals that allow for adequate removal of lactic acid build up. The exception to this would be in sports such as wrestling and basketball which are highly anaerobic in nature and highly dependent upon lactate as an energy source. For these athletes, training in which rest intervals are progressively shortened could be used to allow the build up of lactic acid, thus encouraging an increased tolerance of more acidic conditions. Also to be considered is the size of the athlete. Larger athletes, with more muscle mass will require more rest time for adequate recovery.