Exercise is a powerful tool against the physical effects of aging and it's never too late to start. Being a senior citizen is no reason to avoid exercise, says University of Illinois professor of kinesiology Wojtek Chodzko-Zajko. In fact, any physical activity, like walking even if walking canes must be used, will benefit health. It's important to "choose an activity that you will do," whatever that is, the professor said. "It really matters less exactly what you do than it matters to avoid being completely sedentary." A 1996 report from the U.S. Surgeon General indicates only about 15 percent of adults over 65 get a recommended level of physical activity and as many as one-third get no exercise at all, Chodzko-Zajko noted in an article he wrote for the journal Quest. Chodzko-Zajko suggests that some people might benefit from strategies such as keeping a diary of all their physical activity, including even things like short walks to the store with their walking canes, doing housework or working in the garden. Seeing the diary with their activities written down may help motivate people to exercise because they will want to avoid days in which they have nothing to write. Another trick to encourage increased walking that he likes is getting a dog. The dog will insist on going out for a walk even if the owner might not be in the mood. "Part of the problem may be that we've adopted a medical model of exercise, where exercise is sort of a bitter pill, and you get a prescription and you're expected to stick to it," Chodzko-Zajko said. "But the bottom line is it takes time to change behavior, and I personally feel the broader you can define your activity program, the less likely you are to become demoralized." Even seated exercise is beneficial People who need mobility chairs can still benefit from exercise, although they may have to do it in a seated position. Many of those using mobility chairs have the use of their limbs, but use the chairs because they tire easily. Walking may not be a good exercise choice in this case. Instead, they can try doing leg lifts in a seated position. Start by lifting only one leg at a time to a horizontal position and then put the leg back to vertical. Do this 10 times with each leg to start, working up to three sets of 15 leg lifts per leg. Once this has become easy, lift both legs at the same time, again starting with 10 lifts and working up to three sets of 15 leg lifts. To increase the work load on the leg muscles, ankle weights can be added. Start with one pound per leg and start over at the lowest number of lifts. Exercising the upper body is also important. This can also be done from a seated position. Do a variety of arm exercises. Start with one pound weights at 10 repetitions per exercise. If you don't own any weights, a can of peas from the kitchen is a good substitute. Many web sites and exercise tapes demonstrate exercises for the upper body that can be done while seated.