[EricaB]

Oh boy, my chance to disagree. Walking, running, cycling are great cardio exercises, but I think the best is swimming which seldom gets mentioned. It has much less impact on the body which is important as you age and you get vivid reminders of that from your hips, knees and sometimes ankles. Of course, it is much less expensive buying a pair of running shoes than it is to install a swimming pool in the backyard.