How should I vary my exercise program according to my goal?

Your acute variables (i.e., sets, repetitions, intensities, or rest intervals) help determine the outcome of your exercise program. They are important components that specify how each exercise is to be performed. For instance, if you want to train for endurance, perform more repetitions at lower intensities (low resistance) and allow for short rest periods. If you want to train for strength, lift heavy loads for a few repetitions and increase your rest periods. Sometimes the smallest changes can make a difference in the entire program outcome.