Quite Possibly...

The most ridiculous thing I've ever heard, taken from The About.com Excercise Guide:
Why are football players so susceptible to knee injuries? One explanation comes from New Science which reports on "a condition called SARA (sexually acquired reactive arthritis) in sportsmen, particularly footballers. It seems that footballers have so much sex that they're particularly susceptible to the condition, which in turn makes them more susceptible to...knee injuries."
Wow, and I thought oozing with pus was a bad STD, these guys get knee problems!? The moral of the story, don't sleep with prostitutes who have bad knees...