tried working out fasted if you want the pure edge.
at first this might be hard, because you have been so used to tapping into glucose or caffeine for 'energy'. however when you train fasted your body is in a natural adrenaline state tapping into ketones instead. there is a huge differene in that energy which keeps going, and the energy you get from food or stims which is a going to cause a spike then crash. remember your body will need to digest whatever you put into it, so that will rob it of energy