Not the person you were replying to, but I'm a morning workout person (mostly weightlifting but also some cardio-type stuff). Yeah, empty stomach. For weightlifting I may have a protein shake with just enough water and almost always a banana and that's it. Doesn't bother me. I'm not sure if it's optimal (or if I could even tell what is optimal) but weights are still heavy and I still make progress so I'm happy with it.