Can small-sided games assess the training-induced aerobic adaptations in elite football players?

The aim of this study was to investigate whether or not SSGs could be used to evaluate the aerobic fitness status and the longitudinal training-induced adaptations in football players. Additionally, the capacity of SSGs to recreate the official match demands was investigated.

Twenty-five elite football players were monitored. Total distance (TD), high-speed running, very high-speed running, sprint and accelerations plus decelerations distance were measured during 20 SSGs formats and 25 official-matches; in SSGs, average heart rate was also collected. During submaximal Yo-Yo test, heart rate at peak exercise, heart rate post-60s recovery and rate of perceived exertion were collected. Coefficient of variation, interclass correlation-coefficient and correlation-coefficient analysis were used to calculate validity, reliability, construct validity and, internal and external responsiveness of SSGs demands.

In SSGs, a small variability (~6.0%) with moderate reliability (~0.542 to ~0.663) was found in TD and heart rate, while a high variability (~20.8% to ~60.3%) with poor to moderate reliability (~0.358 to ~0.605) was observed in the other metrics; in submaximal Yo-Yo, heart rate showed small variability (~3.7%) with good reliability (~0.933 to ~0.916). The SSGs demands showed poor internal and external responsiveness (P>0.05) to the training-induced aerobic adaptations as assessed by submaximal Yo-Yo. The construct validity of SSGs showed overall large to very large correlations (r=0.53 to 0.90, P<0.05) between SSGs and official match demands across the season.

SSGs should not replace standardized field tests to detect the training-induced aerobic adaptations. However, SSGs could be confidently used to recreate specific contextual factors in elite football players.