Muscle development can be done through exercise. However, as we age it gets harder to maintain and build muscle with exercise alone. After the age of 40, you start to lose muscle. This process is referred to as Sarcopenia. Why is this a concern? The loss of muscle mass plays an important role in the tendency to fall. Falls can result in fractures and other injuries, particularly in people with weak bones due to osteopenia or osteoporosis. International Osteoporosis Foundation | Bone Health.