Runners run on a track.
Most professional track runners don't get a whole lot of money and so they have to get a second job. Runners like Usain Bolt make a lot of money because of endorsements. Usain Bolt made $20.3 million last year. He probably made $20.2 million just from endorsements.
Tight clothes, unless you Usain Bolt.
passing, same as any other sport.