Went to state on back to back weekends. First weekend was out of gas first day. Extremely sore the rest of the tourney. Next weekend I played most of my doubles matches ( 6 matches in 3 days ) with an endurance runner. We took some Endurox right after each match and I felt better Sunday afternoon than I did on Friday afternoon the week before. I am sure there were other factors but I am sold on it for now.