Has anyone used RIVAL US COMPLX 5? Truly amazing stuff, recovery time between sets are cut in half and can do more reps. Although i find the next day you end up blasting the muscles when you never felt like you pushed it that hard. I guess it helps turn over ATP faster and changes the acid production so you can go past failure without feeling the lactic acid as much. It does that for sure but another thing it does is cramp my stomach a bit.