RULES IN BRIEF Track Events / Field Events / Road Events / Combined Events TRACK Athletes are disqualified if they false-start twice The maximum allowable wind strength for recognition of world or Olympic records is 2 metres per second In events up to 400 metres, athletes must not leave their lane In events of 800 metres and over, athletes may only leave their lane after the break-line, a curved line marked on the track FIELD Athletes taking part in field events may only leave the event area during competition with the permission of a judge, who must accompany the competitor A jump or throw may be disallowed if the athlete exceeds specified time limits between attempts A throw may be aborted halfway through as long as the competitor has not let go of the equipment being thrown or placed a foot out of the throwing circle or runway After each throw, competitors must exit the throwing area from the back of the circle COMBINED The rules for each event in the decathlon and heptathlon essentially match the rules for the individual events, with a few variations, notably: Whereas athletes in the individual track races are disqualified if they false-start twice, decathletes and heptathletes are disqualified after three false starts The maximum allowable wind strength for recognition of world or Olympic records is four metres per second instead of two for track athletes ROAD Walkers must have at least one foot on the ground at all times Walkers must not break into a run, which means that from the moment the advancing foot touches the ground until the leg has reached a vertical position, the leg must be straight; there must be no bend at the knee The nine judges on the walking course may disqualify an athlete on the basis of what the naked eye sees. There is no electronic control Judges may caution walkers with a white warning sign without disqualifying them A walker who receives three warnings is disqualified