Great reviews, positive results and long lasting stamina had me convinced that Muscle Rx is the best pre workout supplement on the market. I’ve had fantastic results with this product. I can feel it working as I’m lifting weights, doing crunches and bench pressing. I can tell it’s working by the way I feel all through the day. Fat is being replaced with muscle even after I leave the gym. Fantastic product! This was exactly the kind of boost I needed.