I reguarly exercise in the morning with an empty stomach, there always has been some ideas around that it's actually quite good for you. Not sure if it's backed up by evidence though. But I've never fainted and felt quite good for having done it first thing in the morning.

I'd say if you didn't want to eat properly before, but are worried, perhaps just have like half a banana or something on your way there or when you wake up.

I think unless you are really going for it at the gym, running for an hour or something, it should be ok.