The benefits of strength training go well beyond toned arms and a firm backside. Strength-training exercises can reduce your risk of heart disease, diabetes and osteoporosis. Stronger muscles make everyday tasks such as lifting your groceries or picking up your child easier. The ideal number of repetitions, or reps, to get those benefits depends upon your goals and training experience.
To achieve the benefits of strength training, the American College of Sports Medicine, or ACSM, offers a general guideline of eight to 12 reps per set, with two to four sets per strength-training exercise and two to three minutes of rest between sets. For older individuals, the ACSM suggests 10 to 15 reps per set using light resistance, and notes that even single sets can help seniors get stronger. The ACSM recommends training each major muscle group two to three times per week, with at least two days of rest between workouts.
Strength-training newbies can see dramatic increases in strength even with light weights and as many as 15 to 25 repetitions per set. Starting with light weights will help you learn proper form safely. The ACSM guideline of eight to 12 reps per set works best for beginning and intermediate lifters. As you get stronger and more experienced, you will likely need to use heavier weights and fewer reps to keep seeing results.
If you have goals such as power or muscular endurance, other rep schemes may work better for you. If your goal is power -- the ability of your muscles to contract forcefully and quickly -- aim for sets of three to six reps with moderate loads. Workouts to build muscular endurance typically involve lighter weights and more reps. The ACSM recommends15 to 20 reps per set for beginning and intermediate lifters.
No single number of repetitions will be ideal over the long haul. Once your muscles adapt to a particular weight and rep scheme, they won't continue to develop. To keep making progress, you'll need to vary the resistance and number of reps. Varying your workouts is called periodization. Linear periodization schemes call for high reps with light weights at the beginning of a program and fewer reps with heavier weights as you get stronger. Undulating periodization plans involve varying reps and weights in a cyclical pattern.
- Medicine and Science in Sports and Exercise: Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory, Musculoskeletal, and Neuromotor Fitness in Apparently Healthy Adults: Guidance for Prescribing Exercise; American College of Sports Medicine
- Medicine and Science in Sports and Exercise: Progression Models in Resistance Training for Healthy Adults; American College of Sports Medicine
Joe Miller started writing professionally in 1991. He specializes in writing about health and fitness and has written for "Fit Yoga" magazine and the New York Times City Room blog. He holds a master's degree in applied physiology from Columbia University, Teacher's College.