Exploratory Analyses of Distance, Load, and Reported Training Surface as Potential Moderators of Resisted Sled Sprint Training: A Systematic Review and Meta-Analysis.

This systematic review and meta-analysis investigated resisted sled training (RST) efficacy compared to unresisted sprint training (UST), alongside the moderating effects of sprint distance, sled load, and surface. Following PRISMA guidelines, PubMed, Web of Science, Scopus and SPORTDiscus were searched up to May 2026. Risk of bias was assessed via the PEDro scale. Twelve studies (N = 324) were included. Data were analyzed using Correlated Robust Variance Estimation (CRVE). Overall, RST reduced sprint times compared to UST (Hedges' g = -0.250, p = 0.046; I2 = 0.0%). While time reductions were significant for early acceleration (≤10 m; g = -0.360, p < 0.001), and not for longer-distance outcomes (>10 m; g = -0.168, p = 0.293), the between-distance interaction was non-significant (p = 0.094). Moderate loads (g = -0.352, p = 0.062) and indoor gym floors (g = -0.495, p = 0.096) showed larger point estimates than natural grass (g = -0.180) and synthetic tracks (g = -0.197). In conclusion, no statistically significant moderating effects of distance, load, or surface were demonstrated. Because training surfaces influence the actual mechanical stimulus, prescribing sled loads based on velocity decrement (%Vdec) rather than percentage of body mass (%BM) is a promising hypothesis to standardize resistance across terrains, requiring confirmation via future prospective trials. PROSPERO: CRD420261415365.