First thing to look for: Did you used to be diligent about exercising, but now there's no time for it? When a person is strapped for scheduling space, one common way to free up a few much-needed minutes is to slack off on exercising. Having other obligations can make it seem advantageous to skip a trip to the gym, and it's easy to quickly fall out of the habit, but that's not good.
Exercise is great for everybody -- its benefits include increased strength, endurance, muscle tone, weight loss and mental alertness, plus lower blood pressure and lower risk for diseases like diabetes and cancer. But exercise is especially great for super-busy people because it both energizes and relaxes. So if you've been skipping sessions on the treadmill, try to make an effort to squeeze them in, even if it's just a few minutes here and there. Sure, you're busy, but without exercise, are you really getting as much done as you could be?