High Quality Content by WIKIPEDIA articles! Sprints are short running races in athletics.Starting blocks are used for all competition sprint and relay events. The starting blocks consist of two adjustable footplates attached to a rigid frame. Races commence with the firing of the starter's gun. The starting commands are "On your marks" and "Set" or "Get Set". Once all athletes are in the set position, the starter's gun is fired, officially starting the race. For the 100m, all competitors are lined up side-by-side. For the 200m, 300m and 400m, which involve curves, runners are staggered for the start.In the rare event that there are technical issues with a start, a green card is shown to all the athletes.