Resistance or "strength" training has repeatedly been shown to be a safe and effective method of reversing sarcopenia, or muscle loss, in the elderly. The condition actually starts around age 45, when muscle mass begins to decline at a rate of about 1 percent per year. Scientists funded by the Agricultural Research Service (ARS) have been studying the factors involved in gradual muscle loss since 1988.
The work is conducted at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston, Mass. Carmen Castaneda Sceppa, a physician specializing in nutrition, led the research at the HNRCA's Nutrition, Exercise Physiology, and Sarcopenia Laboratory (NEPS).
While older adults need strength training to maintain their muscle mass, exercise can also help reduce the risk and symptoms of many chronic diseases, such as arthritis, coronary artery disease, diabetes, frailty, obesity and osteoporosis.
Exercise is by definition different from moderate physical activity. Actual exercise -- by design -- improves the five key components of physical fitness: muscle strength, muscle endurance, body composition, cardio-respiratory endurance and flexibility.
The findings show that in a group of volunteers with osteoarthritis, a joint disease, muscle strength increased by 14 percent and balance improved by 55 percent after a 12-week strength-training program. Flexibility also improved by 17 percent, and pain, based on self reports, decreased by 30 percent.
In another group of volunteers, with chronic kidney disease and on low-protein diets, total muscle fiber increased by 32 percent, and muscle strength increased by 30 percent after 12 weeks of strength training. Those who did not exercise lost about nine pounds, or three percent of their body weight.
Instruction by a trained individual is important for strength-training older adults, according to HNRCA senior exercise physiologist Jennifer Layne, who started a grass-roots exercise initiative for older adults inspired by NEPS studies.