While consistent exercise can make a huge difference in quality and quantity of life, it can't fix everything. Individual differences in response to exercise may determine individual results in muscle building, weight loss, or cardiovascular improvements.
Individuals with other health issues and diseases still need to follow a physician's advice when it comes to disease management protocols. And although exercise alone can not guarantee your health, or cure you of illness, regular physical activity has been shown to help everything from arthritis and heart disease to asthma and diabetes.