Effects of Repeated-Sprint Training Set Structure on Sprint Performance, Force–Velocity Profile, and Repeated-Sprint Ability in Youth Soccer Players

Fernández-Penedo, D, Padrón-Cabo, A, Costa, PB, and Rey, E. Effects of repeated-sprint training set structure on sprint performance, force–velocity profile, and repeated-sprint ability in youth soccer players. J Strength Cond Res XX(X): 000–000, 2026—This study compared the effects of 2 repeated-sprint training (RST) protocols of equal total volume, differing in the number of sprint repetitions per set—low (RST-LRS: 4–6 reps) vs. high (RST-HRS: 8–16 reps)—on sprint performance, horizontal force–velocity (F–V) profile, and repeated-sprint ability (RSA) in youth male soccer players. Nineteen under-16 players were randomly assigned to 1 of the protocols, with both groups completing 12 RST sessions over 6 weeks. Sprint times (5–30 m), F–V profile variables (F 0 , V 0 , Pmax, RFmax, and DRF), and RSA indices (average time, fastest time, total time, and % decrement) were assessed pre- and post-training. Significant improvements were observed in 20-m (−2.3%, p = 0.041) and 30-m (−2.1%, p = 0.026) sprint times, in Pmax (+7.2%, p = 0.037), and in RSA metrics (−3.8% to −4.7%, p < 0.01), with no significant group × time interactions for any variable. These findings indicate that both RST protocols are effective for enhancing sprint performance, maximal horizontal power, and RSA in young soccer players. From a practical perspective, coaches may select either protocol, depending on time constraints and training context, as both produced comparable adaptations when total sprint volume was equalized.