Take In The Beautiful Scenery
Try to exercise at a park or around a lake where you can lose yourself in the beauty of the physical space you are exercising in. Exercising in lovely surroundings has been shown to increase the time spent exercising so you will burn more calories just by exercising in a place that is pleasant to exercise in. This is far better than watching the pedometer machine on a treadmill count the miles you have walked. If you need to know how much you have walked outdoors, buy a pedometer that you clip to your belt. It will measure the amount of steps you are taken and, given your stride length, the number of miles you have walked. It is guaranteed to be more effective if you are exercising in beautiful scenery rather than a stuffy gym.