Resistance training is crucial for increasing and maintaining muscle strength, power, size, and endurance. To achieve each goal, adequate rest between repetitions and sets should be implemented for the best results.

Training for muscular power, we can create blocks within each set or exercise for maximal recovery. For instance, if we do multiple set of 9 repetitions of bench press, we can break down the sets into 3 blocks of 3 repetitions respectively, with 2 minutes of rest between each block and 3 minutes between each set. The rest period allows replenishment of phosphocreatine stores that may help us gain velocity and rate of force production.

Muscular strength training demands similar rest period for power training. Although a study has shown that bench press repetitions decline after 1, 2, and 3 minutes of rest, people who rested 3 minutes have shown smaller decline. However, everyone has different threshold (usually based on age) that after achieving a certain amount of strength gain, longer rest period does not necessarily help him or her get stronger.

For muscular hypertrophy, we should focus on higher repetitions with less rest time between each set. A usual protocol would be 3 sets of 10 to 12 repetitions of bench press (usually 8 exercises total in a workout session) with only 1 minute or less of rest. The emphasis of muscle hypertrophy protocol is to buffer metabolic acids, which increases our stress tolerance when working with weights.

Endurance training protocol is similar to hypertrophy program; we keep the repetitions at 13 to 15 in each set while resting about 1 minute or less before proceeding to the next set or exercise. Endurance protocol helps us increase lactic acid threshold that will help us sustain the intensity of our workout.

Different workout goals require different resting periods. Adequate rest is absolutely crucial to maintain great fitness level. Building and maintaining a great fitness level is like training for a triathlon; a triathlete should be aware of his or her training goals (long or short term) and program the recovery time accordingly.