Effects of high-intensity interval cross training and classical training on physical and sprint performance in male junior sprinters.

High-Intensity Interval Cross Training (HIICT) combines sprinting, plyometric, and functional strength exercises, but its effects compared with classical sprint training in male junior sprinters remain unclear. This study examined the effects of HIICT and Classical Training (CT) on physical and sprint performance in male junior sprinters. Sixty-four male junior sprinters were randomly assigned to an HIICT group or a CT group for an 8-week intervention. Both groups completed similar overall internal training loads. Assessments before and after the intervention included sprint performance, jump performance, ground contact time, strength-related outcomes, anaerobic power, and body composition. Internal load was monitored using session rating of perceived exertion. Training load was comparable between groups throughout the intervention. Compared with CT, HIICT showed more favorable changes in 100-m sprint performance, first-60-m split time, ground contact time, countermovement jump performance, and relative peak power. Squat jump performance improved in both groups, with a greater tendency toward improvement following HIICT. Changes in body composition and several strength-related outcomes were broadly similar between groups, whereas power-clean performance showed a more favorable response in the HIICT group. These findings suggest that, under comparable internal training loads, HIICT may provide additional benefits for sprint-related explosive qualities and acceleration-related performance in male junior sprinters. From a practical perspective, HIICT may be considered as a supplementary training option within junior sprint training programs, particularly when the aim is to target sprint-specific neuromuscular qualities. However, given the specific sample and methodological limitations, these findings should be interpreted cautiously and require confirmation in future studies.