Visit the Fitness Video Library

Story at-a-glance

• Dr. McGuff is a proponent of high-intensity interval training using weights, which is purposed to achieve many of the same results as Peak 8 exercises using cardio equipment
• High-intensity exercise, which engage your fast-twitch muscle fibers, is required if you want an effective aerobic workout, and can cut your workout time from an hour on the treadmill down to 12-15 minutes
• Your fast-twitch fibers are largely glycolytic and store a lot of glucose.