Lifting at any age has rewards, but after 50 it can change your life

...While most older adults are aware they need regular aerobic exercise like walking, swimming, or running to strengthen their heart and lungs and tone their bodies, many do not do any form of weight or resistance training. More and more research is finding that it is, in fact, the only type of exercise that can substantially slow, and even reverse, the declines in muscle mass, bone density, and strength that were once considered unavoidable parts of aging...
http://www.nj.com/healthfit/fitness/index.ssf/2015/04/post_49.html