Sports class/PE =/= Competitive sports.
If they taught you an excessive regimen to follow it'd be incredibly loving boring and you'd never do it.
Most
normal children can't get enough of loving awesome games like dodgeball, and since it calls for constant movement, it's basically a super badass cardio excercise that does nothing but benefit you. I mean, you have a ton of fun, your heart gets stronger, you have more energy. I mean, you'd have to be a loving dumbass to not take advantage of it.