Does The Timing of High-Intensity Interval Training Affect Technical Accuracy Under Fatigue? An Experimental Study in Basketball Players

The scheduling (i.e., timing) of high-intensity interval training (HIIT) during basketball sessions may influence physical development and technical-tactical execution under fatigue, yet limited evidence exists to guide practice. This study compared the effects of early-session HIIT (HIITearly) versus post-session HIIT (HIITpost) on aerobic fitness and technical performance under fatigue in youth basketball players. Thirty-six male athletes (16.5 ± 0.7 years) were stratified and randomly assigned to HIITearly, HIITpost, or control groups in a six-week intervention (2 sessions/week). All groups followed the same HIIT protocol; only timing varied. Physical fitness was assessed via the 30-15 Intermittent Fitness Test (VIFT), and technical accuracy for passes, dribles and shots was assessed during a 3v3 game conducted immediately after the 30-15 test. Results showed a significant improvement in VIFT for both HIIT groups (HIITearly: p < 0.001; HIITpost: p < 0.001), with no change in the control group (p = 0.705). HIITearly led to greater improvements than control in passes accuracy (p < 0.001), shot accuracy (p < 0.001), and dribble accuracy (p < 0.001). HIITpost showed smaller, yet significant, improvements in passes (p < 0.001), shots (p < 0.001), and dribbles (p < 0.001), while the control group exhibited only minor changes. Statistical interactions for all technical variables were significant, with particularly large effects for passes (ηp² = 0.678), dribbles (ηp² = 0.600), and shots (ηp² = 0.610). These findings suggest that both HIIT modalities improve physical and technical capacities under fatigue, with early-session HIIT potentially offering benefits for technical accuracy. However, definitive conclusions should be avoided due to the highly contextual nature of the results. Coaches may consider scheduling HIIT prior to skill-focused activities to maximize performance under fatigue conditions in youth basketball.