Redefining endurance testing in soccer: the reliability and impact of a ball-integrated yo-yo intermittent recovery test

The Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo) is a widely recognized method for assessing aerobic capacity in soccer players. Despite its utility, the test does not incorporate ball manipulation, which is a critical component of soccer-specific endurance. This study aimed to evaluate the reliability of a modified soccer-specific Yo-Yo test (MYo-Yo) that includes ball dribbling, passing, and control, and to compare the physiological responses with those from the conventional Yo-Yo test. Twenty elite male soccer players (mean ± SD: age, 16.4 ± 1 years; height, 173 ± 7 cm; body mass, 65.7 ± 10.4 kg) completed both Yo-Yo tests, with and without ball manipulation. Performance metrics included the number of completed shuttles (Level), total distance covered (Distance; m), and blood lactate concentration (Lactate; mmol/L), while maximal oxygen consumption (V̇O2 max; ml/min/kg) was estimated for all trials. The modified Yo-Yo test (MYo-Yo) demonstrated high reliability, with Intraclass Correlation Coefficients (ICC) of 0.802 for Level, 0.982 for Distance, 0.997 for V̇O2 max, and 0.992 for Lactate (P ≤ 0.001). Comparatively, the MYo-Yo test resulted in significantly lower distances than the standard Yo-Yo test (832 vs. 1520 m, respectively; P < 0.001) and lower lactate concentrations (5.2 vs. 10.9 mmol/L; P < 0.001). No significant correlations were found between the two tests for outcomes (P > 0.05). In summary, integrating ball manipulation in the MYo-Yo test introduces distinct physical and technical demands that influence overall performance. The MYo-Yo test offers a reliable alternative for assessing soccer-specific endurance, better replicating the physical demands encountered during a soccer match.