As much as you want it to be. You can never do a second of sport in your entire time there perfectly easily, or you could go and watch sport (college matches etc) very regularly, or you could play for your college, or play for the university if you were that way inclined. I wouldn't worry about it if not, the 92% figure that gets bandied about is actually a clever* fudge^ of the figures rather than a realistic description. The percentage who due regular sport will probably be higher than most universities due to the collegiate intramural stuff, but nowhere near that high.
* not actually that clever
^ it's the percentage who didn't opt out of a charge for sporting facilities that appeared on their first bill at the university when they were confused and new to the place and didn't really know what all the charges were for (not that I'm cynical or anything).
edit: typo