Arthritis can be a vicious circle. It hurts, so sufferers don't want to move much. But the inactivity brings weight gain and thus more pain to overstressed joints. The way to break the cycle of pain and joint deformities, researchers now know, is exercise. Miriam Nelson, director of the John Hancock Center for Physical Activity and Nutrition at Tufts University, gets a call almost every day from physicians asking for an exercise program for arthritis-ridden patients. Building up muscles with strength exercises helps take the strain off joints, while aerobic exercise can keep off the weight that exacerbates the disease. The Arthritis Foundation recommends stretching, strengthening, and aerobic exercise. It also advises talking with a doctor about what to do during a flare-up. That may include taking pain medications before working out, says the University of Oklahoma's Ross.

Old habits--and old excuses--die hard. But they do die. Ask Tisch, who says he's been at the same weight for the past seven years, thanks in part to his regular workouts. "I feel a lot better, in terms of both a healthier body and outlook," he says. "Now exercise is part of my life. I don't consider it work."