They do take it seriously, and a good reason for this...
at least six brothers close to my age at my hometown congo wwould have played H.S. ball (any sport...myself, football and soccer), and this was our only slightly competitive outlet. Therefore, it was the only way to let off steam. If we had been allowed to play competitvely, we would have probably taken it easier and not been a serious with it..
I tried to organize soccer games with the Spanish congo that met in our hall. it was a blast. It was rough at first (teams were pretty much along congregational lines), but as we got to do it more regularly, it was more relaxed. The teams became more mixed, we always went to eat afterward, and really got along.
Then a C.O. visit...one sister (who didn't have any connection to the players whatsoever) complained. The C.O. said it could raise "Competitve spirits." I answered back, "If we as witnesses weren't competitive, then how do we justify competing fwith the world for the sheeplike ones in service?" Shortly after that, I stepped down.
Now I'm a soccer coach at our school. I look back at regret with not getting to play sports in school, but what can I do about it now? Just have as much fun as I can, I guess.
BTW: did you know the Bethel Gym has a restriction on dunking? Says it's the "spirit of the world." So when I temped and played, I crossed over a lot and finger rolled.