When people think of sports that involve a lot of contact, they usually come up with ones like football or boxing. The thing about those sports, though, is they are supposed to be physical. In football, you bulk up so you can withstand getting body-slammed by a 250-pound man. The running back knows that once he has the football, it’s going to be one brutal hit after another, and any wide receiver knows that a beautiful catch usually ends with an equally gruesome tackle. As for boxing, if you’re not getting hit, you obviously haven’t entered the ring yet.
Then there is swimming. Swimming is most certainly a non-contact sport: apart from swimming in the same pool, you don't even interact with your competitors! However, I have lately discovered that swimming is only a non-contact sport if a) you are competing in a swimming pool with clearly divisive lanes and b) if the pool is relatively empty.
These are all accidental injuries, though, and all acquired while practicing in a public pool. It gets much worse when you engage in an actual competition outside of a neatly sectioned-off pool. At a traditional swim meet, you are disqualified for crossing any body part into a competitor’s lane, never mind making physical contact with the swimmer. In open-water races, however, it’s every man (or woman) for himself. Everyone clumps up into a big mob at the start line (which is usually in the water, so you’re all treading), and when the whistle blows, everyone starts punching, kicking, biting . . . basically everyone drowns one another to get to the front of the pack. And they say swimming is non-contact!
The other sport (the only other sport I "play," in fact) that people mistakenly classify as non-contact is running. Running has an incredible amount of contact—with the pavement! Knee injuries alone demonstrate the physicality of the sport; you don’t get those kind of injuries from tiptoeing across a mattress. Tracks are slightly more cushioned, but imagine trying to train for a marathon on a quarter-mile track: you’d get dizzy! (Never mind bored.)
I may have stopped playing basketball because I wasn't good at bullying the other players (i.e. "Be more aggressive, Goldstein!), but apparently I am still very involved in contact sports!