KMAN Publication Inc. International Journal of Sport Studies for Health 2588-5782 9 Serial Number 27 2026 10 01 Effects of Different Rest-Time Models on Neuromuscular and Performance Outcomes during Short High-Intensity Interval Training in Male Soccer Players Effects of Different Rest-Time Models on Neuromuscular and Performance Outcomes during Short High-Intensity Interval Training in Male Soccer Players 1 11 EN Journal Article 2026 08 02 <table> <tbody> <tr> <td> <p><strong>Objective:</strong> Short-interval high-intensity interval training (HIIT) is widely used in soccer conditioning, yet it remains unclear whether distributing recovery periods differently within a session influences neuromuscular and performance adaptations. This study compared ascending, descending, and constant rest-time models during short-interval HIIT in semi-professional male soccer players.</p> <p><strong>Methods:</strong> Twenty-four players were stratified by playing position and randomly allocated to ascending-rest (A-HIIT), descending-rest (D-HIIT), or constant-rest (C-HIIT) groups (n = 8 each). Participants completed eight preseason HIIT sessions, performed twice weekly. Each session comprised two sets of seven 30-s shuttle-running bouts prescribed relative to individual 30–15 Intermittent Fitness Test velocity. Recovery duration increased progressively in A-HIIT, decreased progressively in D-HIIT, and remained constant in C-HIIT, while total work and recovery time were matched across protocols. Countermovement jump (CMJ), 30-m sprint, 5-0-5 change-of-direction (COD), and Wingate peak power were assessed before and after training. Within-group changes were analysed using Wilcoxon signed-rank tests and between-group differences in change scores using Kruskal–Wallis tests, with Holm correction for multiple comparisons.</p> <p><strong>Results:</strong> All participants completed the intervention, although valid observations varied by outcome because of incomplete or unusable post-intervention data. Before correction, nominally significant within-group changes were observed for CMJ height, sprint time, right- and left-leg COD times, and Wingate peak power (unadjusted <em>p</em> = 0.012–0.046). These changes reflected an improvement only in CMJ height in D-HIIT; the significant sprint, COD, and Wingate changes represented performance decrements. However, none remained statistically significant after Holm correction (adjusted <em>p</em> = 0.180–0.460). No significant between-group differences were found for any outcome (<em>p</em> = 0.191–0.914).</p> <p><strong>Conclusion:</strong> Ascending, descending, and constant recovery distributions produced limited and broadly comparable neuromuscular and performance responses, with no evidence that any protocol was superior. Given the small sample, short intervention, and absence of a non-HIIT control group, these findings should be interpreted as preliminary and hypothesis-generating.</p> </td> </tr> </tbody> </table> https://journals.kmanpub.com/index.php/Intjssh/article/download/5891/11492