Fewer players, bigger opportunity: How structural rule modifications shape physical and technical demands in youth rugby union

Purpose Youth rugby governing bodies have progressively revised competition formats to align game demands with children's developmental characteristics. However, empirical evidence remains limited on whether these structural modifications increase children's locomotor and technical engagement during match play. This study compared locomotor intensity and technical engagement between former (old rules, OR) and revised (new rules, NR) French Rugby Federation (FFR) formats in U8 and U10 rugby players. Methods The revised formats reduced team size from 8 vs 8 to 5 vs 5 in U8 and from 10 vs 10 to 7 vs 7 in U10, while simplifying game structure through the removal or streamlining of some set-piece situations. A total of 214 male players were monitored using 10-Hz GPS and video analysis (U8: 86 players, 45 OR/41 NR; U10: 128 players, 43 OR/94 NR). Locomotor variables included relative distance, sprint distance, maximal in-match speed, accelerations, and time in each locomotor zone, all expressed per minute of effective playing time or as a percentage thereof. Technical variables included successful and unsuccessful passes and tackles, and tries, per minute of effective playing time. Linear mixed-effects models were used. Results In U8, NR was associated with significantly greater sprint distance per minute ( p < 0.001), higher maximal in-match speed ( p < 0.05), greater sprint time proportion ( p < 0.01), and more tries and tackles per minute ( p < 0.001) compared to OR. In U10, NR generated greater technical action frequency across most variables ( p < 0.001), while OR produced greater sprint distance per minute ( p < 0.05). Conclusions The revised NR formats provided children with greater opportunities to move at high intensity and interact with the game, consistent with the aim of creating more age-appropriate game environments through reduced player numbers and simplified game structure.