Scheduling Repeated-Sprint Training on Different Microcycle Days in Professional Soccer Players: A Randomized...

García-Santamaría, A, Padrón-Cabo, A, Fernández-Penedo, D, Costa, PB, and Rey, E. Scheduling repeated-sprint training on different microcycle days in professional soccer players: A randomized crossover study. J Strength Cond Res XX(X): 000-000, 2026-This study compared the acute neuromuscular, mechanical, and perceptual responses to repeated-sprint training (RST) performed on match day minus 4 (MD-4) vs. match day minus 3 (MD-3) in professional soccer players. Seventeen male outfield players completed 2 experimental microcycles using a randomized, counterbalanced crossover design. Each player performed a high-volume RST protocol (3 × 10 × 30 m) on either MD-4 or MD-3, with a 1-week washout in between. External (GPS) and internal (rating of perceived exertion) loads were recorded during RST. Countermovement jump, muscle mechanical properties (MyotonPRO), and perceptual markers (total quality recovery, Hooper Index) were assessed pre- and postintervention (MD-2). No significant differences were found in training load between conditions (p > 0.05). Countermovement jump performance decreased significantly after RST (p = 0.031), with no interaction effect. Delayed onset muscle soreness (DOMS) and fatigue increased in both conditions, but DOMS was significantly higher after MD-3 RST (p = 0.030). Total quality recovery scores also decreased (p = 0.003), with no change in muscle tone, stiffness, or elasticity. These results suggest that although RST elicits similar load regardless of day, performing it closer to match day may increase residual soreness. Coaches are advised to schedule high-intensity RST earlier in the microcycle to optimize recovery and match-day readiness.