Abstract
OBJECTIVE: The purpose of this study is to systematically review and meta-analyze the effects of in-season flywheel resistance training (FRT) compared to traditional resistance training (TRT) on vertical jump and linear sprint performance in team-sport athletes. Additionally, this study aims to explore the moderating effects of training parameters (such as frequency, intensity, and duration) on training outcomes. METHODS: This systematic review and meta-analysis followed PRISMA guidelines and was registered in PROSPERO. Five databases were searched for randomized controlled trials comparing in-season flywheel resistance training (FRT) with traditional resistance training (TRT) on vertical jump and sprint performance in team-sport athletes. Risk of bias was assessed using the Cochrane RoB 2 tool, and evidence quality was graded using the GRADE approach. Data were analyzed using Review Manager and Stata, with subgroup and sensitivity analyses performed. Publication bias was evaluated using funnel plots and Egger's test. RESULTS: Seven randomized controlled trials with 199 male athletes were included. The overall risk of bias was moderate, and evidence quality was low. Flywheel resistance training (FRT) significantly improved countermovement jump (CMJ) height (SMD = 0.46, p < 0.01) and had a small positive effect on linear sprint performance (SMD = -0.38, p = 0.02). Subgroup analyses indicated that CMJ performance improved with training programs consisting of more than 12 sessions, a duration of 5-10 weeks, and a training frequency of less than twice per week. No significant subgroup effects were observed for sprint performance. Sensitivity analyses confirmed the robustness of the results, and no publication bias was detected. CONCLUSION: Compared with TRT, FRT is more effective in enhancing CMJ performance and linear sprint speeds over specific distances in male team-sport athletes during the in-season. Training protocols characterized by low frequency (≤ 2 sessions per week) and a total of around 12 sessions appear to facilitate better athletic adaptations. Future research should include female athletes and investigate long-term interventions to further refine the application strategies of FRT in in-season training.