ABSTRACT
This part introduction presents an overview of the key concepts discussed in the subsequent chapters. The part discusses a major criterion for successful aging, namely, physical activity. It presents a unique approach to actualize a regular program of increased physical activity in older persons. Lifestyle considerations such as regular physical activity and proper nutrition can play critically important roles in helping individuals achieve a healthy and meaningful old age. The part provides the multiple roles that lean muscle plays in a variety of health considerations such as temperature regulation, glucose homeostasis, and a variety of other metabolic issues in addition to its principal functions of initiating bodily movements. It shows that there is an age-related decline in lean muscle mass which starts between the ages of 30 and 50 and accelerates after the age of 70. On a population basis, people are living longer with increased average life expectancies becoming a global phenomenon.
