It’s time to ditch your daily treadmill slog and trade up to an interval training regime that will burn more calories in less time and increase your metabolism. In these videos, Gold’s Gym Fitness Institute trainer Robert Reames explains how to start an interval training program of your own. See how to vary your cardio routine between high-intensity spurts and low-intensity recovery periods to get a high-calorie-burning aerobic workout in just 20 minutes. In addition, Reames shows you four weight-lifting moves that work multiple muscle groups at once so you build more strength in less time. And the more muscle you have, the more calories your body will keep burning when you walk out of the gym. Click on the video below to get started.