When Focusing On Muscle Size Or Endurance, How Long Should You Rest In Between Sets?

Muscular fitness is one part of your overall regimen, consisting of both strength and endurance. While muscular strength is based on the amount of weight that can be lifted in one repetition, endurance is the amount of repetitions that can be completed overall. Training for both strength and endurance requires your muscles to use force to overcome resistance. The resistance can be in the form of weights, body weight or gravity. Specific training guidelines are based on improving one goal or the other.

Training Programs

Weight training programs for improved muscular strength and endurance are based on the overload principle: Muscles must exert force to overcome resistance that is greater than a normal workload. For gains in strength and endurance, the amount of weight used is based on a percentage of the most amount of weight that can be lifted once. This is known as the one rep max, or 1RM, and varies based on the exercises selected. Compound exercises using more than one muscle group have higher maximum weights compared to isolation exercises targeting only one muscle group.

Exercise Selection: Compound vs. Isolation

Weight training programs for improved strength should consist of compound exercises such as the bench press for your chest, shoulder press, lat pulldowns for your back and squats for your legs. Exercises using free weights work more muscle groups, requiring your body to hold the weight while executing the exercise.
Lifting regimens for improved endurance should consist of more isolation exercises such as chest flies, front and lateral shoulder raises, leg extensions and leg curls. Exercises using machines and pulleys can work through muscle failure and a larger range of motion. Bicep and tricep muscles assist the larger muscle groups with compound exercises but are specifically strengthened with isolation exercises.

Guidelines for Strength and Size

Workouts for muscular strength should utilize resistance that is between 60 to 90 percent of your 1RM. Three to four sets of 5 to 12 repetitions are suggested, with a suggestion of one to two minutes' rest between sets of the same exercise and one to three minutes' rest between exercises. Stretching the muscle group while resting helps to activate a higher percentage of muscle fibers. Exercises should be performed slowly for control, using proper form.

Guidelines for Endurance

Workouts for muscular endurance should utilize resistance that is between 50 to 65 percent of your 1RM. Three to four sets of 15 to 20 repetitions are suggested with shorter rest periods of 45 seconds to two minutes between sets and exercises. Flexing the muscle group between sets improves muscle definition. Shorter rest times activate your aerobic metabolism system, elevate your heart rate and help to reduce excess body fat.