I exercised regularly after graduating from college; then lost interest and coasted on my youthful metabolism, then worked out (weight training) with a personal trainer for several years, at home, with my husband. Then I became an animal advocate and age began to catch up with my shape. I have to work very hard to get enough exercise time into the schedule. (VinceNeilsGirl, you are not likely to bulk up and look muscly -- did I spell that okay? -- doing weight work! Believe me, those pro bodybuilders have to WORK to look like that, though I know, I wouldn't want to look "all muscle" at all either).
Exercise is a MUST for me when I start to feel upset or tense. It's amazing how much difference it makes in your mood, isn't it? I find things like reading Shape or Muscle and Fitness magazines very motivating to work out; and ummm, this thread has also worked. Gotta go treadmill now!