Shoo fly

I'm at summer camp again. Moments of free time are few and far between, but I did find time to run one afternoon. In no time I had attracted a cloud of flies. You wouldn't know it, but flies have amazing stamina; they followed me for miles. I tried everything to get rid of them. I swatted them, I ran in zigzags, I stopped abruptly and changed directions, I slowed down then suddenly sprinted. I finally gave up and let them tag along.

Gotta run...