Cooler weather often means more inside workouts. 
Running on a treadmill does not have to be boring or less intense than your outside workout. In fact, running on a treadmill can be a great way to do an interval workout – which can increase calories burned, amp up your metabolism, and increase fitness – when compared to a workout that does not vary intensity.
Give this 30-minute workout a try. If the intensity is too much or not enough adjust up or down. The goal is to vary the intensity over the entire workout.
- Minute 1 4.0 mph
- Minute 2 5.5 mph
- Minute 3 6.0 mph
- Minute 4 6.5 mph
- Minute 5 7.0 mph
Repeat the above 5 more times for a total workout of 30 minutes.