Do hydration breaks alter match dynamics in elite football? An event-based analysis of the group stage of the 2026 FIFA World Cup

Toanalysematch dynamics before and after hydration breaks during the group stage of the 2026 FIFA World Cup, overall and separately for each half. Team-level event data from SofaScore (Opta/Stats Perform) were extracted for all 72 group-stage matches (48 national teams; 1,152 team-window observations). Verified break times anchored four windows per team and half (5-min and full pre- and post-break periods), with exact durations including added time. Twelve indicators were compared as exposure-adjusted rate ratios (RR) using conditional Poisson models with match-clustered robust errors; fouls were analysed at match level. A segmented trend model, score state and red cards were used to separate break-related change from the evolution of each half. No indicator changed in the 5-min windows. Over the full half-periods, the passing rate was lower after the break (first half: RR 0.93, 95% CI 0.88–0.97; second half: RR 0.88, 0.83–0.92), consistent with a within-half decline, with no step at the break (step p ≥ 0.14). Adjusted for the longer post-break periods, fouls did not change (second half: RR 1.07, 0.95–1.21). No pre–post differences were detected around the verified break times; the observed changes were consistent with the gradual evolution of each half.