Background: This study investigated the associations of subjectively and objectively measured physical activity (PA) and sedentary behavior with academic achievement. We further examined whether aerobic fitness, obesity, and bedtime mediate these associations. Methods: This study included 970 children aged 9–15 years (52.3% girls) from 9 schools throughout Finland. Register-based academic achievement [grade point average (GPA)] as well as self-reported and accelerometer-measured PA/sedentary behavior were assessed during spring 2013. Aerobic fitness (assessed via a maximal shuttle run test), body composition (assessed via bioimpedance analysis), and self-reported bedtime were collected. Structural equation modeling was applied to examine the associations. Standardized regression coefficients are presented. Results: Self-reported PA had a direct positive [β = 0.084; 95% confidence interval (CI), 0.023 to 0.145] and an indirect positive association with GPA through higher aerobic fitness (β = 0.061; 95% CI, 0.033 to −0.087). Accelerometer-based PA was not associated with GPA. Self-reported screen time had an indirect negative association with GPA through later bedtime (β = −0.071; 95% CI, −0.096 to −0.035) and lower aerobic fitness (β = −0.039; 95% CI, −0.059 to 0.019). Nonscreen sedentary time had a direct positive (β = 0.193; 95% CI, 0.101 to −0.289) and an indirect negative association with GPA through lower aerobic fitness (β = −0.040; 95% CI, −0.063 to −0.016). Conclusions: Participating in PA, avoiding excessive screen time, and going to bed earlier may benefit academic achievement.
Heidi J. Syväoja, Anna Kankaanpää, Jouni Kallio, Harto Hakonen, Janne Kulmala, Charles H. Hillman, Anu-Katriina Pesonen and Tuija H. Tammelin
Ina M. Tarkka, Pekka Hautasaari, Heidi Pesonen, Eini Niskanen, Mirva Rottensteiner, Jaakko Kaprio, Andrej M. Savić and Urho M. Kujala
Background: Physical activity (PA) is said to be beneficial to many bodily functions. However, the effects of PA in the brain are still inadequately known. The authors aimed to uncover possible brain modulation linked with PA. Here, they combine 4 of their studies with monozygotic twins, who were within-pair discordant in PA for a minimum of 1 year. Methods: The authors performed brain imaging, brain electrophysiology, and cardiovascular and body composition assessments, and collected questionnaire-based data. The present synopsis elucidates the differences associated with differing PA history in conditions without genetic variability. They present new structural and electrophysiological results. Participants, healthy, 45 male monozygotic twins (mean age 34.5 [1.5] y) differed in aerobic capacity and fat percentage (P < .001). Results: More active co-twins showed larger gray matter volumes in striatal, prefrontal, and hippocampal regions, and smaller gray matter volumes in the anterior cingulate area than less active co-twins. Functionally, visual and somatosensory automatic change detection processes differed between more and less active co-twins. Conclusions: In monozygotic twins, who differed in their PA history, differences were observed in identifiable anatomic brain locations involved with motor control and memory functions, as well as in electrophysiological measures detecting brain’s automatic processes. Better aerobic capacity may modify brain morphology and sensory function.