Includes bibliographical references and index.

"Decades of research has demonstrated that regular exercise improves heart and lung function and may relieve joint pain. Daily exercise will help your body to regulate blood sugar levels and reduce inflammation; many of these benefits are a consequence of reducing the amount of body fat you carry around. Your body clearly benefits in many ways from regular exercising. Does the brain benefit as well? Yes, the brain does care whether you exercise, just not always for the reasons that you might think. The brain benefits the most when you perform activities that it evolved to perform--to move around your environment with purpose, not for diversion or sport. Your brain benefits when the movement addresses its unique evolutionary priorities. In order for exercise to influence the brain, the muscles involved must somehow communicate with it. Actively contracting skeletal muscles communicate with the brain, as well as many other organs, by releasing chemical messengers into the blood. During the past few years, many muscle-derived chemical messengers have been discovered. So many, in fact, that your muscles might be more accurately viewed as one of your endocrine glands, similar to your adrenal or thyroid glands. The actions of some of these chemical messengers on your brain, and whether these actions are direct or indirect, beneficial or not, is the focus of this book"--