s fine because to burn fat you need to use the aerobic system, which
you use when
you do mild to moderate activity for a longer amount of time. Exactly why
you rarely see fat marathon runners. If you are really out of shape, do mild activities for a prolonged amount of time, for example, go for a slow walk for an hour, rather than a brisk walk for ten minutes and you will burn more fat that way. The longer you get the aerobic system working for, the more fat you burn.