Strength training can increase muscle mass, preserve bone, and improve strength, power, and balance, which can modify such risk factors for fractures as skeletal fragility, muscular weakness, and deteriorating balance. She and other researchers have worked with women in their 70s, 80s, and 90s in some cases, women in nursing homes who could barely walk unassisted and have shown that weight training can increase their strength, functional status, and outlook. Based on this work, she and her colleagues have devised a practical strength-training program that can be followed at home. Physiological factors other than muscle strength affect the functional status of older women, and identifying those that are most relevant to functional independence is critical to designing effective interventions to prevent or delay dependency. Recently, researchers have begun to explore the role that muscle power plays in this area, said Roger Fielding, PhD, an exercise physiologist at Boston University.
Power is the strength, or force, a muscle can generate when contracting at a rapid rate.
Leg muscle power is required in many basic activities of daily living, such as rising from a chair or climbing stairs. Fielding said that muscle power seems to decline more rapidly and at an earlier age than strength does. This may occur, he reasoned, because both components of power muscle strength and the velocity with which muscle force can be generated decline with age. Med Sci . Fielding said that while these results are provocative, the benefits of strength training are not well enough established to promote as a physical activity.