According to research done at Yale, people who exercise vigorously for at least four hours a week burn more calories even while at rest than people who do not.
Maybe it's just because I have always read a lot, but I thought this was common knowledge. Of course people who exercise regularly have faster metabolisms! Other past reasearch has shown that muscle mass contributes to upping a person's metabolism, so I guess this new research is just another method of explaining why people who exercise regularly burn more calories throughout the day.
Still, it's research worth noting. I think sometimes we look at what our calorie burn is for the amount and type of exercise we are doing, and we lose sight of the fact that the fat-burning effects of our exercise go above and beyond the amount we've just done. It continues throughout the day, as long as we continue to make exercise a regular part of our daily routine.