Hi Chantal. I've heard it over and over again that the idea is to burn more calories than you take in. Therefore, if you eat an english muffin in the morning and you work out and burn 300 calories, you have just burned off the english muffin calories (which is about 120-160 calories), plus some extra calories. In other words, that would be just like not eating an english muffin, and just getting rid of about 180 calories. That's nice and all, but you should still practice eating healthy. :0)