Effects of an 8-week high-intensity interval training program on agility and intermittent endurance in junior badminton athletes

Background and Study Aim. Sport-specific interval training is commonly incorporated into badminton conditioning programs to address the demands of repeated intensive actions performed during play. Training interventions focusing on the integration of sport-specific movement patterns under intermittent loading conditions are applied to influence performance-related outcomes during training and competition. Despite the use of different conditioning approaches, their relative effectiveness when integrated into regular training through sport-specific movement patterns remains a matter of practical interest. This study aimed to examine the effects of integrating an 8-week badminton-specific high-intensity interval training (BS-HIIT) program on agility and intermittent endurance in junior badminton athletes. Materials and Methods. Forty competitive junior badminton athletes (13–17 years) were allocated to either a BS-HIIT group (n = 20) or a control group performing conventional conditioning (n = 20). Both groups trained twice weekly for eight weeks, in addition to regular technical training. The BS-HIIT protocol consisted of court-based, multidirectional movements replicating badminton footwork at 85–95% HR_max, whereas the control group performed general aerobic and agility-based conditioning. Agility was assessed using the Badminton Shuttle Run Agility Test (BSRAT), and intermittent endurance was evaluated using the Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1). A two-way repeated-measures ANOVA, effect size calculations, correlation analysis, and responder analysis were conducted. Results. Significant group × time interactions were observed for agility (η²_p = 0.58) and intermittent endurance (η²_p = 0.62). The BS-HIIT group demonstrated greater improvements in agility (−7.29%) and Yo-Yo IR1 performance (+31.4%) compared with the control group (−2.58% and +10.8%, respectively). A significant correlation between changes in intermittent endurance and agility was found only in the BS-HIIT group (r = −0.64, p = 0.002). A higher proportion of high responders was also observed following BS-HIIT. Conclusions. An 8-week badminton-specific HIIT program is more effective than conventional conditioning in improving agility and intermittent endurance in junior badminton athletes. Integrating sport-specific movement patterns within high-intensity conditioning appears to promote transferable and consistent performance adaptations.