Purpose: Emerging literature suggests that physical activity and fitness may have a positive effect on cognitive and mental health in adolescents. The purpose of the current study was to evaluate the efficacy of two high-intensity interval training (HIIT) protocols for improving cognitive and mental health outcomes (executive function, psychological well-being, psychological distress, and physical self-concept) in adolescents.
Methods: Participants (n = 65; mean age = 15.8 ± 0.6 yr) were randomized to three conditions: aerobic exercise program (AEP; n = 21), resistance and aerobic program (RAP; n = 22), and control (n = 22). HIIT sessions (8-10 min per session) were delivered during physical education lessons or at lunchtime three times per week for 8 wk. Assessments were conducted at baseline and immediately postintervention to detect changes in executive function (trail making test), psychological well-being, psychological distress, and physical self-description by researchers blinded to treatment allocation. Intervention effects were examined using linear mixed models. Cohen's d effect sizes and clinical inference were also calculated.
Results: While results were not significant, small improvements in executive function (mean change (95% CI) -6.69 (-22.03, 8.64), d = -0.32) and psychological well-being (mean change (95% CI) 2.81 (-2.06, 7.68), d = 0.34) were evident in the AEP group; and moderate improvements in executive function (mean change (95% CI) -10.73 (-26.22, 4.76), d = -0.51), and small improvements in well-being (mean change (95% CI) 2.96 (-1.82, 7.75), d = 0.36) and perceived appearance (mean change (95% CI) 0.32 (-0.25, 0.86), d = 0.35), were observed for the RAP group. Mean feeling state scores improved from preworkout to postworkout in both HIIT conditions, with significant results for the AEP (P = 0.001).
Conclusions: This study highlights the potential of embedding HIIT within the school day for improving cognitive and mental health among adolescents.