Designed for sprinters to feign as if they are really working during a long run or warm-up laps, but in reality are just moving their arms in perfect sprinter form, and are moving at an extremely slow pace (an easy jog). When seen from a distance, a coach will be very proud of his sprinters. This saves energy and is characteristic of all sprinters once they get smart enough to utilize this tool.
Freshman: Phew, warm-up laps suck.
Sprint Captain: You actually ran that? Fail. Learn the sprinter shuffle.