Abstract
INTRODUCTION: This study aims to investigate the combining effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) compared to MICT alone on physical fitness, academic performance, and anxiety levels among adolescents in a school setting. METHODS: Sixty male adolescents were randomly assigned to either an experimental group (HIIT + MICT) or a control group (MICT only) for 12 weeks. Physical fitness was assessed using lung capacity, a 50-meter sprint, a standing long jump, and a 1000-meter run. Anxiety levels were measured using the Zung Self-Rating Anxiety Scale, and cognitive performance through academic evaluations. Statistical analyses included Shapiro-Wilk, Mann-Whitney U, unpaired t-tests, chi-square, and McNemar tests. RESULTS: After 12 weeks, the experimental group showed a significant increase in lung capacity (10.30 ml/kg) compared to the control group (3.18 ml/kg, P = 0.03). Sprint and run completion times were also significantly faster in the experimental group (P < 0.01 and P = 0.02), with greater improvements in the long jump (P = 0.01). Academic performance and anxiety levels improved significantly in the experimental group (P = 0.02 and P < 0.01), while the control group exhibited no significant changes. CONCLUSION: This study demonstrated that combining HIIT with MICT results in greater improvements in adolescent cardiorespiratory fitness, anaerobic performance, academic outcomes, and anxiety levels compared to MICT alone. These findings support the incorporation of HIIT alongside traditional MICT in adolescents. TRIAL REGISTRATION: The study was retrospectively registered in the clinical trials registry on 26/04/2023 (ChiCTR2300070895).