Effects of a school-based physical activity program on retinal microcirculation and cognitive function in adolescents

Objectives: To investigate the effect of combined aerobic and coordinative exercise on retinal microcirculation and its association with changes in cognitive performance in healthy adolescents. Design: Using cluster-randomization (on class-level), 36 participants were allocated to an exercise group (EX) performing a 20-min aerobic and coordinative exercise session on each school day over a period of 8 weeks or a control group, which was encouraged to have social interactions (CON). Method: Prior to and following the intervention period, central retinal arteriolar (CRAE) and venular diameters (CRVE) were assessed by use of a static vessel analyzer. Additionally, a computer-based version of the Stroop Color-Word task was administered to assess inhibitory control. Results: The statistical analysis revealed that EX compared to CON showed higher CRAE at post-test, when pre-test values were accounted for, F(1,32) = 4.92, p = 0.036, eta(2) = 0.130. In contrast, no such effect was reported for CRVE. With regard to cognitive performance, a greater reduction of reaction time on the Stroop task was observed in EX relative to CON, F(1,30) = 8.58, p = 0.006, eta(2) = 0.222. The increase in CRAE was significantly correlated with a decrease of reaction time on trials demanding inhibitory control, even after adjusting for covariates, r(31) = -0.438, p = 0.011. Conclusions: A structured exercise program leads to a widening of retinal arteriolar diameters, which is associated with improvements in inhibitory control. Consequently, daily exercise sessions performed during the school break-time can be recommended for promoting both cardiovascular and cognitive health in adolescents. (C) 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.