Validity of the Yo-Yo intermittent recovery test level 1 in assessing or estimating VO2max among female soccer players
The indirect V O2max prediction from the YYIR1 has been performed to date using the general estimation formula recommended by Bangsbo et al. (2008), which is based on the total distance covered during this test. Unfortunately, the authors did not specify the gender and physical characteristics of the 141 subjects, from whom this prediction formula was derived. It is very likely that the majority, if not all of these subjects, were male players. Thus, it is still unknown if this formula will yield accurate results to predict the V O2maxof female soccer players. Additionally, it has been shown that gender distinct prediction equations provide a more accurate estimation of V O2maxwhen a similar field test (20-m shuttle run test) is used (Stickland et al., 2003). Consequently, the purpose of the present study was to evaluate the validity of the YYIR1 in assessing or estimating V O2maxamong female soccer players in comparison to a maximal laboratory treadmill test (LTT). 2. METHODS Eighteen female soccer players (age, 21.5 ± 3.4 years; height, 165.6 ± 7.5 cm; body mass 63.3 ± 7.4 kg) competing in the 2nd German National League participated in this study. They signed a written informed consent after receiving verbal and written explanation of the study procedures and its potential risks.