The multi-stage fitness test, also known as the pacer test, is a series of stages that have different tasks sometimes used by sports coaches and trainers to estimate an athlete's VO2 max (maximum oxygen uptake). The most common variation of the multi-stage fitness test is the FitnessGram/Cooper PACER test. The test is especially useful for players of sports such as rugby, association football, Australian rules football, Gaelic football, hurling, hockey, netball, handball, tennis, squash, and fitness testing in schools and colleges plus many other sports; employed by many international sporting teams as an accurate test of cardiovascular fitness, one of the more important components of physical fitness. The test was created in 1982 by Luc Léger, University of Montreal and published in 1983 with a starting speed of 8 km/h and stages of 2 min duration. The test was re-published in the European Journal of Applied Physiology in 1988 in its present form with a starting speed of 8.5 km/h and 1 min stages under the name "The multistage 20 metre shuttle run test for aerobic fitness". Result equivalences between slightly modified versions are well explained by Tomkinson et al. in 2003.
VO2max = (Velocity (km/h) × 6.65 - 35.8) × 0.95 + 0.182
[METs] = VO2max / 3.5
The test involves running continuously between two points that are 20 m apart from side to side. The runs are synchronized with a pre-recorded audio tape, CD or laptop software, which plays beeps at set intervals. As the test proceeds, the interval between each successive beep decreases, forcing the athletes to increase their speed over the course of the test until it is impossible to keep in sync with the recording (or, on extremely rare occasions, until the athlete completes the test). Many people who test people using the multi-stage fitness test allow one level to beep before the person makes the line, but some middle and grade schools allow two missed laps. If the person being tested does not make the next interval, the most recent level they completed is their final score.