If you search for articles online about working out on an empty stomach, you’ll probably come across recommendations to do so because it will “boot your metabolism”, or some crap. That’s all B.S. There is no *benefit* to working out on an empty stomach and as a trainer, I don’t advise doing so for two reasons: firstly, you may not have enough energy to really get as good a workout in if you had eaten beforehand and secondly, because your muscles don’t really have much reserve to work from.
As a normal person with a busy schedule, I say it’s okay if you can’t eat before you workout, but I do recommend at least drinking some BCAAs (Branched-chain amino acids) beforehand. BCAAs will still somewhat ‘feed’ your muscles before your workout when you don’t have food in you. Ideally, you should eat a source of carbs and protein before a workout because you are more likely to get a better workout in and your body has some fuel for power, but if it’s more convenient for you not to eat, then don’t. You will turn out just fine!
Personally, I’ve done it both ways. I used to have more time to eat before my workouts, but lately, I’ve been working out first thing and I have some BCAAs and pre-workout beforehand and then I eat breakfast afterwards. I’m still doing fine and I’m still getting in good workouts. I’m not training for anything specific, so it’s okay that I’m doing it this way.
So, to sum it up… if you can’t eat, have BCAAs and if you can eat, then eat!