ACSM'S Health & Fitness Journal:
Departments: Fitness Focus Copy-and-Share
This copy-and-share column provides practical information on strength training.
Dixie L. Thompson, Ph.D., FACSM, is the director of the Center for Physical Activity and Health and a professor in the Department of Exercise, Sport, and Leisure Studies at the University of Tennessee, Knoxville.
Strength training, weightlifting, and resistance exercise are terms for the use of techniques to improve muscular fitness. Many types of exercises can be used to improve strength. Some examples include traditional weightlifting exercises using barbells, exercises like push-ups that do not require equipment, and strengthening exercises that use resistance bands. In each case, the person performing the exercise is causing the muscle to work against a resistance that will lead to muscular adaptations and increases in strength. Traditionally, strength training was common primarily among athletes and bodybuilders. However, the value of strength training is now recognized for almost everyone, and benefits go well beyond increasing strength.
BENEFITS OF STRENGTH TRAINING
Muscles get stronger when they work against a resistance greater than they normally encounter. For competitive and recreational athletes, this may result in improved performance, but increases in strength also can provide important benefits for everyday life. For example, having greater strength will make common chores like lifting boxes less taxing. For older adults, the ability to lift and carry a bag of groceries will help maintain functional independence. Research has shown that even people older than 90 years can still develop muscular strength when they perform regular strengthening exercises. Strength training also has a positive impact on bone health. In younger people, regular strength training can increase bone formation. Although bone is lost through the aging process, strength training can slow this loss. Achieving and maintaining good bone strength is important for avoiding osteoporosis and lowering fracture risk. Evidence also suggests that regular resistance exercise can be beneficial in helping to control blood glucose levels, an indicator of diabetes.
There is controversy about the role of strength training for weight loss. The types of strength training programs that most adults perform do not burn a great deal of calories and thus are less advantageous than aerobic activity for creating a caloric deficit. But muscle is a metabolically active tissue, and a person with more muscle will have a higher metabolic rate. There also is some evidence that lifting weights when dieting will help minimize the loss of bone.
BASIC STRENGTH PROGRAM
The American College of Sports Medicine (ACSM) recommends that adults engage in muscle-building exercises on at least two nonconsecutive days each week. Individuals should perform 8 to 10 exercises in some combination of upper body, lower body, and core (abdomen and back) activities. The number of repetitions to complete with each exercise is dependent on goals, but 8 to 12 repetitions is the standard recommendation. Generally, more weight, and thus fewer repetitions, will yield greater increases in strength. Less weight and more repetitions will develop muscular endurance. Some warm-up activities (i.e., light aerobics and stretching) are recommended before beginning a strengthening session. Taking time to warm up will lower your chance of injuries and improve your muscles' ability to perform the exercises. If you have joint problems, high blood pressure, or cardiovascular disease, it is best to consult your physician before beginning a weightlifting program.
A fitness professional can help you select exercises and develop a program that will be best for your individual needs. You also can gather more information about strength training from the ACSM Web site (www.acsm.org). Look for the downloadable brochures under the Resources for the General Public link.
Brought to you by the American College of Sports Medicine www.acsm.org