upper body training today with my buddy who personal trains for xsport. he had this new pre workout supp hes trying, called SAN fierce. we both took a serving 10 minutes before our workout and it gives nasty pumps. not only that but the energy kick is substantial, and about 2 hours after the workout, you KNOW you rocked yourself. my back is already sore. the NF.. anybody have any negative experience with supps similar to this? i had a friend who freaked out on NO-Xplode and almost had a heart attack, but he had freakishly high blood pressure to begin with.