This treadmill workout combines two-minute runs with challenging walk/jog sections—plus a mini sprint at the end. It utilizes longer periods of effort and switches between speed training and challenging inclines to raise your heart rate, burn calories, and improve your endurance.
If you're just starting a workout routine, doing gazelle-being-chased-by-a-lion sprinting intervals will be just as painful as they sound. Ease into it by doing a brisk walking workout that includes short and slow jogging intervals. This lower-impact