If you thought the Fitness Marshall had a lot of subscribers, Pamela Reif's numbers are even better ... but you can also find channels that incorporate HIIT and other calorie-burning approaches.

Hers reports: SELF, DanceWithDeepti, and Body Project are top YouTube channels for calorie-burning workouts. Cardio and HIIT excel; short videos burn fewer calories.

Hers reports: SELF, DanceWithDeepti, and Body Project are top YouTube channels for calorie-burning workouts. Cardio and HIIT excel; short videos burn fewer calories.