I recently got a membership to this sports club and I started going to the gym there (first time). First time, I did light machine workouts on the machines at 30-40lbs. About 2 hours later I played tennis and I was amazed at the results! I moved extremely fast and hit extremely hard without trying. All I was trying to do was grind and I beat my opponent 6-1 6-1. I was surprised at the easiness to play bc of working out. However, yesterday I worked out again (2nd time) and did more machines than I did the first time but at 40-60lbs and benchpressed a bit. I felt pretty SORE and after a few hours later I went to play tennis and it was HORRIBLE. I could not move fast. Sure i hit hard, but I was really ticked off at my footspeed because footwork and speed is very important to me. I felt SLUGGISH and LAZY. Does anyone know what happened?