Keeping active and remaining fit can help prolong your life and can even help prevent or delay illnesses or disabilities as you grow older. The benefits of physical activity extend throughout life and can improve many health conditions. Being active helps lower your risk of falls and developing heart disease and diabetes and can help you live on your own longer. Fitness and physical activity are safe for most older adults—even for those with stable chronic conditions, such as heart disease, diabetes, and arthritis. Your doctor can advise you about the safety of certain activities and increasing your fitness level. The September 3, 2008, issue of JAMA includes an article reporting that regular physical activity can improve mental function in older adults with memory complaints. This Patient Page is based on one published in the July 12, 2006, issue of JAMA.