No, it's not. I usually do this. Usually the only free time I have during the week is early morning before work. No way I have the time to eat, wait for it to digest and workout. So I immediately workout, take a quick shower, then eat breakfast. As long as I ate a good meal the night before, this never posed a problem for me. Much better than going into a workout full. If you need to, drin an easily digestible whey product beforehand. I dont do that, but if I were to consume something that would be it.