The validity and the reliability of yo-yo intermittent recovery test 2 (yirt2) to estimate maximal oxygen uptake

The Yo-Yo Intermittent Recovery Test 2 (YIRT2) that designed mainly to estimate VO2max in soccer players, it used to assess athletes abilities to repeatedly perform highintensity exercise. The purpose of the present study was to determine the validity and reliability of the Yo-Yo Intermittent Recovery Test 2 (YIRT2) to estimate maximal oxygen uptake (VO2max) in elite female futsal players. Subjects were Iranian elite female futsal players (n = 33: mean age 22.46±3.04 yrs, height 164.1±4.85 cm, and body mass 56.6±7.31 kg). All subjects performed a graded exercise test on motorized treadmill to examine VO2max by breath to breath gas analyzer apparatus (K4B2, COSMED, Italy) and the YIRT2 to estimate VO2max. The significant correlation found between VO2max measured by gas analyzer and estimated by YIRT2 (r=0.88, r2=0.77, P=0.001), indicating that the YIRT2 is valid test toestimate VO2max.Test-retest results showed that the YIRT2 is the reliable test to estimate VO2max (r=0.98, r2=0.96, P=0.001).Discussion and It is concluded that YIRT2 were a valid and reliable test to estimate VO2max in elite female futsal players. The YIRT2 appears to measure aerobic fitness but may also be used as a field test of the ability to repeat high-intensity efforts.