Probably music. We have a 35,000 year old flute, and if you take a good look at this flute, this clearly isn't the first time someone made a flute, it's quite sophisticated. Singing predates any instruments, Dan Marek in Singing: the first art actually muses that the first being to make an instrument might have been trying to imitate the human voice.

The oldest evidence of sports, however, dates only to a few thousand years BC (I'm finding different numbers as I have a look around), and the oldest sport would be wrestling.