The Yo-Yo Test: Reliability and Association with a 20-m Shuttle Run and VO2max

Purpose: The purpose of the study was to determine the reliability of yo-yo intermittent recovery test (yo-yo) scores and their degree of association with a 20-m shuttle run (20MSR) and VO 2max values. Methods: Subjects were elite (Australian Football League [AFL], n = 23), state-level (hockey, n = 15, and cricket, n = 27), and recreational team-sport players (n = 33). All performed a 20MSR and the yo-yo at either level 1 (recreational and state level) or level 2 (AFL). A recreational subgroup (n = 19) also performed a treadmill VO 2max test. Results: Test–retest results found the yo-yo (levels 1 and 2) to be reliable (ICC = .86 to .95). The 20MSR and yo-yo level 1 scores correlated ( P < .01) in the recreational ( r = .81 to .83) and state-level groups ( r = .84 to .86), and 20MSR and yo-yo level 2 scores, in the elite ( r = .86) and recreational groups ( r = .55 to .57). The VO 2max and yo-yo level 1 scores in the recreational group correlated ( P < .01, r = .87), but no association was found with yo-yo level 2 ( r = .40 to .43, non significant). Conclusions: We conclude that level 1 (recreational and state level) and level 2 (elite) yo-yo scores were both strongly associated with 20MSR scores and VO 2max (level 1: recreational subjects only). The yo-yo appears to measure aerobic fitness similarly to the 20MSR but may also be used as a field test of the ability to repeat high-intensity efforts.