Aerobic and Muscular Fitness Associations with Adolescent Cognitive Control

Abstract

PURPOSE: Physical activity supports greater cardiorespiratory fitness (CRF); a correlate of cognitive control. The relation of muscular fitness (MF) and cognitive control are less clear. The present study investigated the differential relationship of CRF and MF with cognitive control in older adolescents; a population subjected to social and academic stressors. METHODS: Students (15-17 years, N = 289, 122 females) from ten secondary schools completed tests of inhibition, working memory (WM), CRF (PACER), and MF (standing long jump, push-ups). RESULTS: Stepwise regression analyses accounted for demographic factors in step 1, and either CRF or MF in step 2. CRF predicted flanker response accuracy (RA) and reaction time (RT) across congruency conditions (ß’s ≥ 0.14, p’s < 0.05). In the 1-back WM task, CRF predicted greater RA, greater d', and shorter non-target RT (ß’s ≥ 0.15, p’s < 0.05). In the 2-back WM task, CRF predicted greater non-target RA and d' (ß’s ≥ 0.14, p’s ≤ 0.05). Comparatively, MF only predicted 2-back target accuracy (ß = 0.14, p = 0.02). Follow-up 3-step regressions assessed significant outcomes from the 2-step models to account for the contrasted fitness variable in step 2, and the fitness variable of interest in step 3. CRF remained a significant predictor for most cognitive outcomes (ß’s ≥ 0.17, p’s ≤ 0.05). However, with MF entered in step 2, CRF marginally predicted incongruent flanker RA and 1-back non-target accuracy (ß’s ≤ 0.16, p’s ≥ 0.06), and no longer predicted greater 2-back d' (ß = 0.11, p = 0.20). Comparatively, MF marginally predicted 2-back target accuracy with CRF accounted for (ß = 0.12, p = 0.09). CONCLUSION: MF was unrelated to cognitive performance, especially with CRF included in the model. CRF’s predictability of WM decreased with MF accounted for, particularly during conditions requiring greater WM demands. CRF was generally related to faster processing speed and greater RA during a task modulating inhibitory demands, suggesting that increased CRF may improve cognition via modulation of older adolescents’ inhibitory control. Such findings highlight physical activity’s value in aiding cognition underlying older adolescents’ academic performance. Project funded by the National Health and Medical Research Council (APP1120518).