The more total calories you burn the more fat you lose
"It's true that the body burns a higher percentage of calories from fat during more mellow exercise like walking and easy cycling. But, when you pick up the pace for a higher-intensity cardio workout, you burn a greater number of overall calories (which should be your focus for weight loss) and subsequently just as much total fat. What's more, high-intensity exercise kicks your metabolism into high gear even after you're done working out." Accoding to Prevention Magazine Fitness Director Michele Stanton. Read all about it here.