One of the biggest trends now sweeping the US fitness industry is 'spinning.' This is not an idea that came from Shane Warne or Spiderman, but rather a new, high-tech enhancement on stationary biking. In a spinning class, riders work out side by side for 45 minutes to an hour on sophisticated bikes in an ambience more usually associated with a night club. Lights are low, the music is amped up, and instead of a performer on a stage there is an instructor on a lead bike barking out motivational instructions.