Yo-Yo Intermittent Recovery Level 2 Test in Pubescent Soccer Players with Relation to Maturity Category

Abstract

The purpose of this study was to investigate the influence of maturity category on the Yo-Yo intermittent recovery level 2 test (YYIR2) in pubescent soccer players. Twenty-six soccer players aged 12.7±0.2 yrs participated in the study and were divided into two groups (Under and Over) by maturity category according to their peak height velocity curves. Maximal oxygen consumption (VO₂max), onset of blood lactate accumulation (OBLA), running economy (RE), fat-free mass (FFM), thigh muscle cross-sectional area (MCSA) by magnetic resonance imaging and distance in the five-jump test (5J) were measured to monitor the development of aerobic capacity and muscle strength, and correlations with the YYIR2 were investigated. The YYIR2 for Under and Over were 255.0±48.2 m and 336.0±71.1 m, respectively, and significant difference was found between the groups. The YYIR2 was significantly correlated with 5J, and the correlations with FFM and MCSA were also significant regardless of whether the data were expressed in absolute or relative value to height. In contrast, no relation with the YYIR2 was found in VO₂max relative value to weight, OBLA and RE, it was suggested that the YYIR2 might not be a good indicator for aerobic development in pubescent soccer players. These results indicated that maturity category affected the YYIR2 of pubescent soccer players due to physique and the development of muscle strength.