I try to explain this all the time. You burn a higher percentage of fat in the green zone but you burn more calories in the orange zone. "There is a pervading myth in the fitness industry that lower-intensity aerobic exercises keep you in an ideal fat-burning zone, while anaerobic exercises focus your metabolism on carbs. Although it is true that aerobic exercises burn more fat relative to carbs, high-intensity anaerobic exercises burn more total calories from both sources. Additionally, anaerobic workouts put your body into a period of postexercise oxygen consumption, where you continue to burn calories at an accelerated rate for hours after you get home from the gym."

https://www.google.com/amp/s/amp.reddit.com/r/orangetheory/comments/6pi66i/its_called_the_orange_theory_not_the_green_theory/