One of my teammates used to use that stuff to stay awake at work. He ended up staying up the night before a tournament and decided to drink 3 jack3ds and a rockstar. He was so pumped he got onto the mat and ended picking up the guy and slamming him.
Be very careful with taking that stuff or any energy supplement for that matter. I personally was addicted to monster and rockstar. breaking that addiction was terrible.
Yea its the caffeine and stims in it. Breaking it is a little bad. I use to use them all the time non stop and then stopped and you just have to get by the first 3-4 days imo than it feels better.