These days it seems if I play a tough 2 or 3 setter match that same night and the next day I get the most horrible kind of tightening of my thigh muscles and hamstring area such that If I had a match the next day I could not play. I am 33 and playing tennis since I was like 14. Played sport in general since I was like 8. In college this never happened to me so what could be the reason now? Recently I won my semi in 2 tough sets but suffered the same cramps and tightening and lost my final which was the very next day. My opponent had two days extra rest and I basically played him on one leg. Him being a pusher and me an aggressive baseliner I had to run around alot and lost in 3 tight sets. Whilst cramping and hobbling from the end of the first set onwards. IT has been two days since the final and the pain is slowly going down but I am having trouble walking up and down the stairs. In your opinions what do you think explains this and what has happened to me? Thanks for your time.