http://www.helpingyoucare.com/22627/harvard-health-publishes-report-on-strength-and-power-training-a-guide-for-adults-of-all-ages

Harvard Health Publishes Report on Strength and Power Training: A guide for adults of all ages

By Editor, On October 9th, 2012

"According to a special health report issued by Harvard Health Publications of Harvard Medical School, “Sarcopenia—the gradual decrease in muscle tissue—starts at around age 30, [and] the average 30-year-old can expect to lose about 25% of muscle mass and strength by age 70 and another 25% by age 90.”

“Some of these changes stem from the physiological effects of aging, but disuse plays a bigger role than many people suspect. Studies of older adults consistently prove that a good deal of the decline in strength can be recouped with strength training,” the report states."