Effects of functional training on linear sprint and change-of-direction performance in soccer players: a systematic review and meta-analysis

Background Functional training is increasingly incorporated into soccer conditioning; however, its effects on linear sprint and change-of-direction (COD) performance remain unclear. This systematic review and meta-analysis evaluated the effects of structured functional training on linear sprint and directional-change performance in soccer players. Methods PubMed, Web of Science, Embase, SPORTDiscus via EBSCOhost, Scopus, and the Cochrane Library were searched from database inception to 6 July 2026. Randomized controlled trials comparing structured functional training with usual soccer training, no additional training, or other non-functional training conditions were included. Pooled effects were calculated as Hedges’ g with 95% confidence intervals (CIs) using random-effects models. Exploratory subgroup analyses were conducted according to intervention duration, weekly training frequency, and sprint distance. The certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Results Ten randomized controlled trials involving 260 soccer players were included. Functional training significantly improved pre-planned COD performance (nine trials; n = 240; Hedges’ g = −0.72, 95% CI −1.23 to −0.22; p = 0.005; I 2 = 71%) and linear sprint performance (seven trials; n = 164; Hedges’ g = −1.00, 95% CI −1.54 to −0.46; p = 0.0003; I 2 = 61%). Leave-one-out sensitivity analyses showed that the direction and statistical significance of both pooled effects were retained after exclusion of individual studies, although the magnitude of the COD and sprint estimates was influenced by Zhao et al. and Doungchan et al., respectively. No statistically significant between-subgroup differences were identified according to intervention duration, weekly training frequency, or sprint distance. Conclusion Structured functional training may improve linear sprint and pre-planned COD performance in soccer players. However, the magnitude of the pooled effects should be interpreted cautiously because of between-study heterogeneity, the influence of individual studies, and the limited evidence base. Current evidence is insufficient to establish an optimal training prescription or to extrapolate these findings to reactive agility or match performance. Systematic review registration https://www.crd.york.ac.uk/PR , identifier CRD420261441220.