I think that's a very important question. Are you ever too old to exercise? And I think you're not. (Katz walks on treadmill.) For example, it was long thought that people with arthritis should not exercise. Now, it's been well documented in many studies that people with osteo-arthritis will improve their joints, will be able to have less pain, less disability with a certain amount of exercise. I'm not talking about vigorous exercise, but I'm talking about walking and that type of exercise. I find it very stimulating psychologically as well as physically. I think it's important for my mental health as well as for my physical health and that's why I do it.