I'm very guilty of this! Often times I hit Healthtrax in the morning which means I just get dressed and hop in the car and go! When I wake right up I'm not usually ready to eat right away. BUT if your overall goal is to lose weight you have to eat a little something!
When your body has an empty stomach and you start working out your body goes into survival mode. It's trying to reserve whatever energy you have so your metabolism slows. Basically you do all the work with little to no benefit. UGHHH I'll be packing a banana for the car ride next time!