- Last Updated: Saturday, 07 February 2015 06:17
The test involves running continuously between two points that are 20 m apart. These runs are synchronized with the pre-recorded audio track, which plays beeps at set intervals. As the test proceeds, the interval between each successive beep reduces, forcing the athlete to increase velocity over the course of the test, until it is impossible to keep in sync with the recording.
The recording is typically structured into 23 'levels', each of which lasts around 63 seconds (the shortest level is level 16, lasting 60.45 seconds, the longest is level 2, lasting 67.8 seconds). Usually, the interval of beeps is calculated as requiring a speed at the start of 8.0 km/h, increasing by 0.5 km/h with each level. The progression from one level to the next is signaled by 3 rapid beeps. The highest level attained before failing to keep up is recorded as the score for that test.