See the article at Religion Dispatches for a discussion of this question. It seems to me that in one sense, sport is not worth dying for, given that it is a form of play, albeit serious play. As the author of the piece points out, the real question is whether or not sport is worth the risk of death, which is present in many sports. I would answer that yes, at least some sports are worth the risk of death, because for some they are near-necessary elements of a flourishing human life. I'm not arguing that we should not seek to make sports as safe as possible--so the changes to the Olympic luge run might be justified, as are whatever can be done in the NFL to prevent brain damage from head trauma--but I do believe that we should not go to the other extreme and make physical safety the primary concern that trumps all others. When I ride my bicycle on the country roads of Madison County, it is generally pretty safe. However, in some sense I'm risking my life, as all it takes is one distracted or drunk driver to end my existence, or just one mistake by me on the bike sending me hurtling into concrete, asphalt, or barbed wire. Of course, we all risk our lives when we go to the grocery store, cross the street, go to work, and so on. I won't be hang gliding or sky diving any time soon, but as soon as the snow and ice go away and the temperature climbs back above freezing, I'll be back on my bike, riding carefully.
HT: Rob Sica