We've always seen exercise as something done in hopes that eventually--one day far, far in the future--we might actually get hit on again. But, for some people, the payoff is much more immediate. It happens while they're exercising. That's right: Some people get hit on even when they're sweaty, pony-tailed, makeupless and Spandexed. On Saturday mornings at White Rock Lake, whether you're walking, running, pedaling, rolling or just walking the dog, you're a moving target in the city's biggest singles scene.