The rules of track events, as observed in most international athletics competitions, are formulated by the International Association of Athletics Federation (IAAF). Key rules of track events relate to three phases — starting, running and finishing.
Starting
Starting position for a sprint race

- The start of a race is marked 5 cm wide by a white line. In all races, that are not run in lanes, the start line must be curved, so that all the athletes run the same distance upto the finish.
- Starting blocks shall be used for all races up to and including 400 meter (including the first lap of the 4x100 and 4x400) and shall not be used for any other race. No part of the starting block overlaps the start line or extend into another lane.
- In most international competitions, the command of the starter is “on your marks” and “set” for crouch start and “on your mark” for standing start.
- Any sprinter with a false start is considered disqualified.
- Athletes are not permitted to run inside the inner curve of the track. They have to run in their designated lanes only.
Running
- In all races that are run in lanes, athletes have keep themselves their allocated lanes from start to finish. This also applies to any portion of a race run in lanes.
- If an athlete leaves the track or steps on the line demarking the track, this will be considered disqualified.
- An athlete, after voluntarily leaving the track shall not be allowed to continue in race.
- Any athlete found intentionally obstructing the path of another runner is also disqualified from the race.
- There are races that start in lanes and then at a “break line”, the competitors merge. Examples of this are the 800 meters and 4x400 relay race.
Finishing
The finish of a race is marked by a white line 5 cm wide. Competitors are placed in the order in which any part of their torso (as distinguished from the head, neck, arms, legs, hands or feet) reaches the vertical plane of the nearer edge of the finish line.
The measurement of time shall be taken from the flash or the smoke of the gun to the finishing touch, which shall be recorded in 1/100th of a second if taken manually. Fully automatic timing (FAT) is required for high level meets.
Finishing position for a sprint race
