[unop]

Typically, this is the glib superficial answer a non-runner would have.

To a runner, you are your own opponent, your feet and the terrain the challenges and the elation and endorphin rush afterwards the goal/reward.

And watching running, well, watching capable elite runners glide effortlessly or outdoing themselves with a surge from deep within - it's kinda exhilarating just willing them on. And if that's not sport.. Not sure what qualifies :)

[uwagar]

sure, a 100m sprint is interesting. running by oneself is kinda psychotic. one being one's opponent is quite a private experience not a spectator sport.