If your interested in trying out a simple interval training routine to increase your caloric burn and add to your speed try this simple 45 minute interval workout routine:
5 mins 3.0-4.0 Walk (very, very brisk walk)
10 mins 5.0-6.5 Run
5 mins 3.0-4.0 Walk
10 mins 5.0-6.5 Run
5 mins 3.0-4.0 Walk
10 mins 5.0-6.5 Run
And then cool down for 5 minutes (which actually makes this 50 minutes)
This is great for those individuals that are new to interval training. If you need more a challenge try increasing the incline by a percentage of 3-5 or simply increase the speed. I have been doing a variation of this routine for a couple of weeks now and the calorie burn was amazing.