The 15-Minute Interval Training Workout
Banish gym boredom and get fitter faster by incorporating intervals—short, high-energy bursts of exercise interspersed with lower-intensity exercise—into your cardio regimen. Research has shown you’ll burn more calories and build endurance in surprisingly little time. This routine, created by Billy Blanks Jr., host of the Dance With Me Cardio Fit DVD ($15, amazon.com), is designed for a treadmill, but you can do similar moves on an elliptical trainer or a bike, or outside in a hilly area ( just estimate your pace). Start at the suggested speed, or as close to it as you can, and pick up the pace gradually until you feel challenged.