Do small-sided games prepare players for the worst-case scenarios of match play in elite young soccer players?

The aim of the study was to determine whether the physical performance of young soccer player during various small sided games (SSGs) underloads, replicates or overloads the requirements of the worst-case scenarios (WCS) during match play. A total of 521 SSGs’ individual observations and 15 different formats of SSGs with different areas per player (ApP) (ApP100: < 100; ApP200: ranged from 101 to 200; ApP300: > 201, all in m² ·player^-1) were taken into consideration. Whole (90-min average; OM) and 15-, 5- and 1-min worstcase scenarios (WCS15, WCS5 and WCS1, respectively) were analysed. Total distance covered relative (m·min^-1) (TDCR), high-speed distance relative (m·min ¹) (HSDR), very high-speed distance relative (m·min-1) (VHSDR) and sprint distance relative (m·min^-1) (SDR), player load relative (PLR) and both total (ACCR) and high intensity relative accelerations (n·min^-1) (ACCHR) were collected. All external load measures analysed were significantly higher in WCS1 compared to WCS of longer duration and SSGs with different ApP (p < 0.001). The analysis demonstrated interactions between game type and player positions (p < 0.001) for TDCR, VHSDR, PLR and ACCHR. The SSG formats did not sufficiently stimulate the WCS for locomotor demands (VHSDR and SDR). SSGs played on an ApP100 overestimated the mechanical values compared to WCS15 and WCS5. The analysed SSG formats did not sufficiently stimulate players to cope with all external load demands that occurred during WCS1. This study provides useful information for practitioners on the heightened impact of different SSG formats on external load in relation to the WCS of competitive match play.