Hello I sweat more than anyone else I know. I compete in local tourneys and few if anyone is in better shape than I am. I can't seem to last longer(cramping) than 2 hours of playing. I understand that Patrick Rafter had cramping problems too. Does anyone know what he did to combat this? I drink lots of water all day long. Drink up to 2 gallons of Gatorade in an hour but still can't keep up. Also, I take Ca, Na, Pa, Mg suppliments too. Any suggestions?