Me and my friend had decided to lose weight and buff up. He decided to use a pre workout supplement, I decided not to. Big Mistake on my part. He was able to outlast me during our workouts, he was gaining muscle mass and losing weight. I on the other hand, was getting no where. I was exhausted when we left the gym and he was stilled pumped. I changed my point of view, and ordered my own bottle of muscle rx. You learn something new everyday.