I work out at 6:30am. I use nothing… I work out in a fasted state from dinner the night before (or even an extended fast). That said, some people find that taking some Himalayan salt with a big glass of water appx 30 min before exercise helps.
I’m up by 4.30am for first training session of the day and I do this fasted. I’ll have coffee, or sometimes BPC, but that’s all. I am also currently trialing Celtic Sea Salt preworkout – about half a tsp in a glass of water.