Popsugar Fitness Workouts Cardio Workouts 36 Cardio Workouts to Burn Major Calories at the Gym July 4, 2016 by Leta Shy View On One Page Photo 2 of 5 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 2 Treadmill Workouts Beginner: 300-calorie walk-jog workout 30-minute interval workout 40-minute workout for new runners 20-minute quick treadmill hike Intermediate: 30-minute pyramid intervals 20-minute incline workout 45-minute "on a hike" workout 45-minute gym plan, including 30 minutes on the treadmill and a 15-minute strength-training session Advanced: 40-minute mountain hike 45-minute belly-fat-blasting workout 45-minute treadmill workout All Levels: Take your pick: three-level metabolism-boosting treadmill run 30-minute, celeb-approved interval workout 500-calorie interval workout that's easy to adjust to make more or less challenging 45-minute treadmill interval mashup Previous Next Start Slideshow WorkoutsCardio WorkoutsRowing