Hailey A Cowell 
Physical Activity Guidelines for Americans and A Review of Scientific Literature Used (DVD) [PDF ebook] 

Being physically active is one of the most important steps that Americans of all ages can take to improve their health. This book provides science-based guidance to help Americans aged 6 and older improve their health through appropriate physical activity. The guidelines in this book are designed to provide information and guidance on the types and amounts of physical activity that provide substantial health benefits. The main idea behind these guidelines is that regular physical activity over months and years can produce long-term health benefits and realizing these benefits requires physical activity each week.