A very difficult topic, because it doesn't say anything directly on the topic.
Thanks to Dave, I've recently read an essay on the topic which was quite helpful. It essentially saw sport as a neutral activity, but one in which it is very easy for sin to be masked as acceptable.
I'll be posting more on this as I work through it, but my current thought is about Sport as a revealer. I don't think that sport necessarily produces greater ungodliness, but is instead a revealer of ungodliness that is already there. In short, it reveals the person underneath.
This, however, can also be a beautiful thing when great sportsmanship and honourable play are demonstrated, or pursuit of excellence without cheating despite great pressure to do so. The high-emotion arena of sport is "a true revealer of character" as the great Stan Coombs once said.
What do you think about competitive sport, is it a good part of our created humanity? Or just pride dressed up in respectability?