10-second barrier

Its significance has become less important since the late 1990s, as an increasing number of runners have surpassed the ten seconds mark.

For sprints, World Athletics maintains that world records and other recognised performances require: a wind assistance of not more than two metres per second (7.2 kilometres per hour (4.5 mph)) in the direction of travel; fully automatic timing (FAT) to one hundredth of a second; and no use of performance-enhancing substances.

[2] Times were recorded manually to one tenth of a second; three official timers with stopwatches noted when the starting gun flashed and when the runner crossed the finish line, and their median recorded time was the official mark.

Some races also had an unofficial FAT, or semi-automatic time, often in conjunction with photo finish equipment.

The first person timed at under ten seconds was Bob Hayes, who ran 9.9 s in April 1963 at the Mt.

[7] Hines went on to win the 1968 Olympic 100m in 9.9 s, rounded down from his FAT of 9.95, making it the first non-wind-assisted electronic sub-10-second performance.

Both of these marks were recorded at a high altitude, which aids performance due to lower air resistance.

[9] The 2008 season saw a new high for sub-10 second performances: 14 runners achieved the feat a total of 53 times between them, the highest ever for either figure.

Only two months into the start of the outdoor track season, 2011 became a record-breaking year as fifteen men ran under ten seconds between April and June.

On 29 May 2016, former World Champion Kim Collins improved his personal record by running 9.93 +1.9 in Bottrop as a 40-year-old.