Could sex decrease your stamina and hamper your athletic performance?

No: That's something coaches make up to keep you from dropping from the team over a girlfriend. If it were true, the National Football League would enforce celibacy. That being said, many relationships consume a great deal of time and emotional energy, and if sports and school are also important to you, it will be a balancing act.

No: only if you are up all night and have poor performance to to a lack of sleep.