@exyle if you want to burn calories, training your legs it's a good way, Legpress it's not a good idea, there are other's leg exercise that you can do and burn more calories, such as Barbell Deadlift, Barbell Squat, and Dumbbell Lunges. Avoid machine exercises like Legpress, all the exercises I told you, exercise the legs and the core at the same time, they are more efficient in reducing weight.