What is the test of whether an activity is a "sport"?

For example, I imagine most of us would agree that chess, cheerleading, and ballroom dancing are not "sports", even though they require skill and training. By what test do these fail to constitute "sport", while football succeeds?

This is prompted by an article in the paper, discussing the question and insisting that golf is not a sport. But I'll withhold the cite for now, to let our own brains function independently.

Since nobody seems to have risen to the bait of this post, could I suggest that a perfect definition, applicable to all sports, is, "...A way of wasting time, money and effort in approximately equal proportions..."

Thank you for the editorial, but can we get back to the word-related question?

I have always thought that "sport" is an activity where you use physical exercise, and in fact the dictionary seems to validate that. Yet, then ballroom dancing would be a sport, and it really isn't. I would consider cheerleading a sport, though. Car racing? NO! I have always had a hard time considering golf a sport, especially when golfers use a golf cart. Yet, how can it be a sport for some and not for others. Interesting question, Shu!