Love should be the drug of choice for athletes, according to this somewhat tongue-in-cheek column By Stephen Moss in  The Guardian. In the third item, he asks a psychologist whether falling in love could have made tennis star Andy Murray a better player.

Falling in love jacks up levels of oxytocin, making you cuddlier and friendlier," he explained, "so on an gormless electro-chemical level a case could be made that it's bad for a sportsman. But falling in love could also liberate you from fear and produce the right balance between a desire to win and a desire to have fun. It could lead you to feel 'sod it, what does it matter?'