An examination of the prospective association between physical activity and academic achievement in youth at the population level

Bidirectional Associations Between Adiposity and Cognitive Function and Mediation by Brain Morphology in the ABCD Study

Importance

Most epidemiologic studies examine the brain as an outcome in relation to adiposity (ie, the brain-as-outcome perspective), but it is also a potential risk factor associated with adiposity accumulation over time (ie, the brain-as-risk factor perspective). The bidirectionality hypothesis has not been fully explored in adolescent samples previously.

Objective

To assess bidirectional associations between adiposity and cognitive function in youth and test mediational pathways through brain morphology (specifically the lateral prefrontal cortex [LPFC]), lifestyle behaviors, and blood pressure.

Design, Setting, and Participants

This cohort study uses data (wave 1-3; 2 years of follow-up) from the Adolescent Brain Cognitive Development (ABCD) Study, a long-term longitudinal investigation of brain development in the United States launched in 2015, which recruited 11 878 children aged 9 to 10 years at inception. Data analysis was performed from August 2021 to June 2022.

Main Outcomes and Measures

Multivariate multivariable regression analyses were used to assess bidirectional associations of indicators of cognitive function (eg, executive function, processing speed, episodic memory, receptive vocabulary and reading skills) and adiposity (eg, body mass index z scores [zBMI] and waist circumference [WC]). Mediators considered for this investigation were lifestyle variables (eg, diet and physical activity), blood pressure, and the morphology of the LPFC and its subregions.

Results

A total of 11 103 individuals (mean [SD] age, 9.91 [0.6] years; 5307 females [48%]; 8293 White individuals [75%] and 2264 Hispanic individuals [21%]) were included in the current study. Multivariate multivariable regression analyses revealed that higher baseline zBMI and WC were associated with worse follow-up episodic memory (β, -0.04; 95% CI, -0.07 to -0.01) and better vocabulary (β, 0.03; 95% CI, 0.002 to 0.06) task performance, in covariate adjusted models. Similarly, superior baseline executive function (zBMI: β, -0.03; 95% CI, -0.06 to -0.01; WC: β, -0.04; 95% CI, -0.07 to -0.01) and episodic memory (zBMI: β, -0.04; 95% CI, -0.07 to -0.02; WC: β, -0.03; 95% CI, -0.06 to -0.002) task performance were associated with better follow-up adiposity status in covariate adjusted models. Cross-lagged panel models with latent variable modeling had a bidirectional association with executive function task performance (brain-as-outcome: β, -0.02; 95% CI, -0.05 to -0.001; brain-as-risk factor: β, -0.01; 95% CI, -0.02 to -0.003). The hypothesized associations were statistically mediated by LPFC volume and thickness, physical activity, and blood pressure.

Conclusions and Relevance

In this cohort study, executive function and episodic memory were bidirectionally associated with adiposity indices over time in this adolescent sample. These findings suggest that the brain can be both a risk factor and an outcome of adiposity; this complex bidirectional association should be taken into account in future research and clinical practice.

Sport Participation and Academic Performance in Young Elite Athletes

Strong evidence supports physical activity and fitness levels being positively associated with cognitive performance and overall academic performance in youth. This also applies to sports participation. However, whether participation in sports at the elite level is associated with greater academic performance remains unknown. Thus, the present study aimed to compare the academic performance of young elite athletes to that of control students, as well as to analyze whether the type of sport mediates these results. Between 2010 and 2019, all students from the last Baccalaureate course of the Spanish Elite Sport High School-which also includes non-elite athletes and recreational athlete students, who were categorized as controls-participated in this study. Academic performance was assessed through both the grade point average of the two last Baccalaureate courses and through the average grades from the University Entrance Examinations. Athletes were categorized attending to different sport classifications. A total of 1126 adolescents (570 girls, 18.2 ± 0.6 years) participated in the study, of which 483 and 643 were categorized as elite athletes and control students, respectively. Elite athletes attained a lower overall academic performance than controls (p < 0.001), which was confirmed for both sexes (p < 0.001). These differences were separately confirmed for most academic subjects (p < 0.05), as well as when attending to different sport classifications (all p > 0.05). Young elite athletes attained a lower academic performance than their non-elite peers, regardless of their type of sport. These findings highlight the importance of programs aimed at facilitating dual careers among young elite athletes.

Correction: An examination of the prospective association between physical activity and academic achievement in youth at the population level

[This corrects the article DOI: 10.1371/journal.pone.0253142.].

Examining the relationships among adolescent health behaviours, prefrontal function, and academic achievement using fNIRS

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Prior studies document effects of lifestyle behaviors on the brain and academics.

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Among adolescents we found that activity and eating both predict task performance.

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Activity also predicts functional activation in the right lateral dlPFC, but not grades.

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Substance use predicted worse grades but not brain-related mediators.

Several adolescent health behaviours have been hypothesized to improve academic performance via their beneficial impact on cognitive control and functional aspects of the prefrontal cortex (PFC). The primary objective of this study is to examine the association between lifestyle behaviours and academic performance in a sample of adolescents, and to examine the extent to which activity within the PFC and behavioural indices of inhibition may mediate this relationship. Sixty-seven adolescents underwent two study sessions five days apart. Sleep and physical activity were measured using wrist-mounted accelerometry; eating habits, substance use and academic achievement were measured by self-report. Prefrontal function was quantified by Multi-Source Interference Task (MSIT) performance, and task-related activity via functional near-infrared spectroscopy (fNIRS). Higher levels of physical activity predicted higher MSIT accuracy scores (β = .321, ρ = 0.019) as well as greater activation within the right dlPFC (b = .008, SE = .004, ρ = .0322). Frequency of fast-food consumption and substance use were negatively associated with MSIT accuracy scores (β = −0.307, ρ = .023) and Math grades (b = −3.702, SE = 1.563, ρ = .022), respectively. Overall, the results of this study highlight the importance of lifestyle behaviours as predictors of prefrontal function and academic achievement in youth.