Good morning to all. Has anyone out there used a Preworkout to help with workouts? I have a friend who is wanting me to try one, but I'm a little scared. Do they work? Do I need it? She is also on a fat burner. We are both at the stage we have 5 pounds to go. She is on Roxy Lean. Any info on either one of these would be great! I appreciate your time. Have a great Saturday!