I am sorry if I can not really get into the admiration thing. Doing sports seems to be a very self-centered, egoistical thing. The only thing I can accept is that it motivates people to push harder and explore boundaries of human achievement. Also, some medical knowledge might also actually be gained (like how to train effectively - this could matter a lot in a world of office workers with little time for exercise). But for those effects the expense seems a bit high.
Also in the light of those benefits I think drugs (doping) should be legalized for professional sports. Those people ruin their bodies anyway, letting them experiment with drugs can only lead to more medical knowledge.