I recall the time when I moved into a new apartment complex soon after my wedding. One of the most peculiar things I noticed was that there were hardly any exercise faddists and very few morning/evening walkers. But the situation has changed dramatically lately. Almost everyone I know, young or old, is out exercising nowadays. Awareness that exercise is good for health has increased greatly, but surprisingly, most individuals do not seem to know the more specific benefits that accrue from exercise beyond controlling weight and benefiting the heart.  

Exercise is a treatment advice for osteoarthritis, congestive heart failure, multiple sclerosis and Parkinson's disease. Whether the aim is wellness or disease management, the exercise aspect of the treatment is just as important as its dietary component.
Like guidelines for diets, exercise guidelines have also evolved over the years. In the past, doctors were apprehensive of allowing exercise for heart patients. But currently, cardiac rehabilitation works on the principle of progressive exercise. Gradually building up the intensity of exercise in such patients improves the ability of the heart to pump effectively.
Benefits of exercise are being observed in more and more conditions. People afflicted with joint and neuromuscular disorders benefit immediately from exercising.
Osteoarthritis without exercise can be crippling, but the pain and stiffness in joints can be reduced by exercising. Knee and hip replacement surgeries are common today. Successful surgery has to be followed by an appropriate exercise programme to achieve fully functional joints.
People suffering from chronic conditions such as diabetes derive dual benefit from exercise. Not only does exercise lower blood sugar, it also releases the "feel-good hormones".
People suffering from chronic pain and fatigue get immense relief by exercising appropriately. But the kind of exercise required may vary with the disease or health status.
Patients of multiple sclerosis benefit from water exercises. Aerobics and resistance training can help people afflicted with chronic obstructive lung disease. This form of exercise also improves the ability to function independently and enhances walking speed and balance in Parkinson's patients.