1.   Thousands of people have been practicing step aerobics, but over-enthusiasm could leave them flat on their backs.

2.   The American team of Jenni Meno and Todd Sand, by comparison, left them flat.

3.   The Buffaloes not only knocked the Huskers from the top of the BCS, they pushed them down the Rockies and left them flat on the Great Plains.

4.   Those casual fans miss the years of intense physical and psychological buildup that can leave athletes flat after the Olympic torch is extinguished.