Improved frontoparietal white matter integrity in overweight children is associated with attendance at an after-school exercise program

Multimodal neuroimaging correlates of physical-cognitive covariation in Chilean adolescents. The Cogni-Action Project

Health-related behaviours have been related to brain structural features. In developing settings, such as Latin America, high social inequality has been inversely associated with several health-related behaviours affecting brain development. Understanding the relationship between health behaviours and brain structure in such settings is particularly important during adolescence when critical habits are acquired and ingrained. In this cross-sectional study, we carry out a multimodal analysis identifying a brain region associated with health-related behaviours (i.e., adiposity, fitness, sleep problems and others) and cognitive/academic performance, independent of socioeconomic status in a large sample of Chilean adolescents. Our findings suggest that the relationship between health behaviours and cognitive/academic performance involves a particular brain phenotype that could play a mediator role. These findings fill a significant gap in the literature, which has largely focused on developed countries and raise the possibility of promoting healthy behaviours in adolescence as a means to influence brain structure and thereby cognitive/academic achievement, independently of socioeconomic factors. By highlighting the potential impact on brain structure and cognitive/academic achievement, policymakers could design interventions that are more effective in reducing health disparities in developing countries.

Sex Differences in the Relationship Between Nucleus Accumbens Volume and Youth Tobacco or Marijuana Use Following Stressful Life Events

Background

Exposure to stressful life events (SLEs) can upset balance and affect the healthy brain development of children and youths. These events may influence substance use by altering brain reward systems, especially the nucleus accumbens (NAc), which plays a key role in motivated behaviors and reward processing. The interaction between sensitization to SLEs, depression, and substance use might vary between male and female youths, potentially due to differences in how each sex responds to SLEs.

Aims

This study aims to examine the effect of sex on the relationship between SLEs, Nucleus Accumbens activity, and substance use in a nationwide sample of young individuals.

Methods

We utilized data from the Adolescent Brain Cognitive Development study (ABCD), a longitudinal study of pre-adolescents aged 9-10 years, comprising 11,795 participants tracked over 36 months. Structured interviews measuring SLEs were conducted using the Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS). Initial linear regression analyses explored if SLEs could predict volumes of the right and left NAc. Subsequently, Cox regression models were used to investigate how SLEs and NAc volume might predict the initiation of tobacco and marijuana use, with the analysis stratified by sex to address potential sex differences.

Results

Our findings reveal that SLEs significantly predicted marijuana use in males but not in females, and tobacco use was influenced by SLEs in both sexes. A higher number of SLEs was linked with decreased left NAc volume in males, a trend not seen in females. The right NAc volume did not predict substance use in either sex. However, volumes of both the right and left NAc were significant predictors of future tobacco use, with varying relationships across sexes. In females, an inverse relationship was observed between both NAc volumes and the risk of tobacco use. In contrast, a positive correlation existed between the left NAc volume and tobacco and marijuana use in males, with no such relationship for females.

Conclusion

This study underscores that the associations between SLEs, NAc volume, and subsequent substance use are influenced by a nuanced interplay of sex, brain hemisphere, and substance type.

Comparative efficacy of physical activity types on executive functions in children and adolescents: A network meta-analysis of randomized controlled trials

OBJECTIVES

This study investigates the impact of various physical activity (PA) types on executive functions (EFs) in children and adolescents.

DESIGN

A systematic review and network meta-analysis of randomized clinical trials.

METHODS

We searched databases such as PubMed, Embase, Cochrane, and Web of Science up to April 2023, including randomized controlled trials involving 6 distinct PA types for healthy children and adolescents. The Cochrane risk of bias tool was used to assess the risk of bias, and a random-effects model in STATA 17.0 was used to calculate standardized mean differences (SMDs) and 95 % confidence intervals (CI).

RESULTS

Ball Games emerged as the most effective modality for improving updating accuracy, securing a SUCRA score of 94.4 %, and for reducing inhibition reaction time, with a SUCRA score of 94.8 %. Cognitively Engaging Physical Activity led in improving inhibition accuracy with a SUCRA score of 71.7 %. Dance excelled in improving update accuracy and reducing shifting reaction time, with SUCRA scores of 86.6 % and 99.5 %, respectively.

CONCLUSIONS

PA has a significant benefit in EFs in children and adolescents, however the size of the effect varies by type of PA. Ball Games emerged as the most efficacious modality for enhancing updating accuracy and for expediting inhibition reaction time. Cognitively Engaging Physical Activity proved to be the preeminent strategy for improving inhibition accuracy. Dance was distinguished as the optimal approach for improving updating accuracy and reducing shifting reaction time.

Mediating role of inhibitory control in relationships between cardiovascular fitness and academic achievement in preadolescents

Cardiovascular fitness (CRF) has been consistently linked to cognitive performance and academic achievement, and inhibitory control has been recognized as a key predictor of academic success. However, few studies have explored whether inhibitory control mediates the relationship between CRF and academic performance in children, and the existing findings are inconclusive because of certain limitations. This study investigated the mediating role of inhibitory control in the association between CRF and academic achievement among preadolescents while also addressing the related limitations. This study enrolled a total of 175 elementary school students (70 girls, mean age=11.17years, standard deviation=0.7), who participated in a half-mile test for assessing their CRF level. Additionally, inhibitory control was measured using the Stroop Color and Word Test (Stroop test), and language and mathematics tests were administered to measure their academic performance. The results revealed that the participants with higher CRF levels achieved superior performance in tasks requiring a high level of inhibitory control (r=0.291, P<0.001) and in Chinese language (r=-0.415, P<0.001) and mathematics (r=-0.366, P<0.001) tests even when gender, age, and body fat were considered. Furthermore, a mediation analysis revealed that inhibitory control, as measured through the incongruent trials of the Stroop test, partially mediated the relationship between CRF and academic performance (language: indirect effect=-0.013, 95% CI [-0.019, -0.008]; math: indirect effect=-0.013, 95% CI [-0.021, -0.009]). These findings have major implications for child development, emphasizing the key role of inhibitory control in the beneficial effects of CRF on academic achievement.

The effects of physical activity on white matter microstructure in children with overweight or obesity: The ActiveBrains randomized clinical trial

Background

Emerging research supports the idea that physical activity benefits brain development. However, the body of evidence focused on understanding the effects of physical activity on white matter microstructure during childhood is still in its infancy, and further well-designed randomized clinical trials are needed.

Aim

This study aimed: (i) to investigate the effects of a 20-week physical activity intervention on global white matter microstructure in children with overweight or obesity, and (ii) to explore whether the effect of physical activity on white matter microstructure is global or restricted to a particular set of white matter bundles.

Methods

In total, 109 children aged 8 to 11 years with overweight or obesity were randomized and allocated to either the physical activity program or the control group. Data were collected from November 2014 to June 2016, with diffusion tensor imaging (DTI) data processing and analyses conducted between June 2017 and November 2021. Images were pre-processed using the Functional Magnetic Resonance Imaging (MRI) of the Brain´s Software Library (FSL) and white matter properties were explored by probabilistic fiber tractography and tract-based spatial statistics (TBSS).

Results

Intention-to-treat analyses were performed for all children who completed the pre-test and post-test DTI assessment, with good quality DTI data (N = 89). Of them, 83 children (10.06±1.11 years, 39 % girls, intervention group=44) met the per-protocol criteria (attended at least 70 % of the recommended sessions). Our probabilistic fiber tractography analysis did not show any effects in terms of global and tract-specific fractional anisotropy (FA) and mean diffusivity (MD) in the per-protocol or intention-to-treat analyses. Additionally, we did not observe any effects on the voxel-wise DTI parameters (i.e., FA and MD) using the most restricted TBSS approach (i.e., per protocol analyses and p-corrected image with a statistical threshold of p < 0.05). In the intention-to-treat analysis, we found that our physical activity program had a borderline effect (p-corrected image with a statistical threshold of p < 0.1) on 7 different clusters, including a cluster in the corpus callosum.

Conclusion

We conclude that a 20-week physical activity intervention was not enough to induce changes in global and tract-specific white matter during childhood. The effects of physical activity on white matter microstructure could be restricted to local changes in several white matter tracts (e.g., the body of the corpus callosum). However, our results were not significant, and more interventions are needed to determine whether and how physical activity affects white matter microstructure during childhood.

Move Your Body, Boost Your Brain: The Positive Impact of Physical Activity on Cognition across All Age Groups

While the physical improvements from exercise have been well documented over the years, the impact of physical activity on mental health has recently become an object of interest. Physical exercise improves cognition, particularly attention, memory, and executive functions. However, the mechanisms underlying these effects have yet to be fully understood. Consequently, we conducted a narrative literature review concerning the association between acute and chronic physical activity and cognition to provide an overview of exercise-induced benefits during the lifetime of a person. Most previous papers mainly reported exercise-related greater expression of neurotransmitter and neurotrophic factors. Recently, structural and functional magnetic resonance imaging techniques allowed for the detection of increased grey matter volumes for specific brain regions and substantial modifications in the default mode, frontoparietal, and dorsal attention networks following exercise. Here, we highlighted that physical activity induced significant changes in functional brain activation and cognitive performance in every age group and could counteract psychological disorders and neural decline. No particular age group gained better benefits from exercise, and a specific exercise type could generate better cognitive improvements for a selected target subject. Further research should develop appropriate intervention programs concerning age and comorbidity to achieve the most significant cognitive outcomes.

Reallocation of time between preschoolers' 24-h movement behaviours and executive functions: A compositional data analysis

The objectives of the survey were to explored the associations of the 24-h movement behaviours (MB) with executive functions (EFs) and quantified the predicted changes in EFs following allocation of time among behaviours. In the cross-sectional survey, 135 preschoolers (3 ~ 5 years) were enrolled. Physical activity (PA) and sedentary (SED) time were objectively measured employing an ActiGraph GT9X. Sleep time was reported by parents. EFs were assessed using the iPad-based Early Years Toolbox which is a collection of computerized tasks consisting of brief tasks assessed from games administered and scored according to protocol. To explore the associations of the 24-h MB with EFs, compositional multiple linear regression was employed. To quantify the predicted changes in EFs following allocation of time among behaviours, compositional isotemporal substitution was used. Moderate-to-vigorous physical activity (MVPA) was positively related to cognitive flexibility. Replacing sleep or SED with MVPA was associated with positive changes in cognitive flexibility. When MVPA was replaced with sleep or SED, the predicted detriments to cognitive flexibility were larger than predicted benefits of replacing sleep or SED with MVPA. The findings highlight the key role of intensity of PA for preschoolers' EFs and the importance of meeting recommended levels of MVPA.

Associations Between Socioeconomic Status, Obesity, Cognition, and White Matter Microstructure in Children

Importance

Lower neighborhood and household socioeconomic status (SES) are associated with negative health outcomes and altered brain structure in children. It is unclear whether such findings extend to white matter and via what mechanisms.

Objective

To assess whether and how neighborhood and household SES are independently associated with children's white matter microstructure and examine whether obesity and cognitive performance (reflecting environmental cognitive and sensory stimulation) are plausible mediators.

Design, Setting, and Participants

This cross-sectional study used baseline data from participants in the Adolescent Brain Cognitive Development (ABCD) study. Data were collected at 21 US sites, and school-based recruitment was used to represent the US population. Children aged 9 to 11 years and their parents or caregivers completed assessments between October 1, 2016, and October 31, 2018. After exclusions, 8842 of 11 875 children in the ABCD study were included in the analyses. Data analysis was conducted from July 11 to December 19, 2022.

Exposures

Neighborhood disadvantage was derived from area deprivation indices at participants' primary residence. Household SES factors were total income and highest parental educational attainment.

Main Outcomes and Measures

A restriction spectrum imaging (RSI) model was used to quantify restricted normalized directional (RND; reflecting oriented myelin organization) and restricted normalized isotropic (RNI; reflecting glial and neuronal cell bodies) diffusion in 31 major white matter tracts. The RSI measurements were scanner harmonized. Obesity was assessed through body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), age- and sex-adjusted BMI z scores, and waist circumference, and cognition was assessed through the National Institutes of Health Toolbox Cognition Battery. Analyses were adjusted for age, sex, pubertal development stage, intracranial volume, mean head motion, and twin or siblingship.

Results

Among 8842 children, 4543 (51.4%) were boys, and the mean (SD) age was 9.9 (0.7) years. Linear mixed-effects models revealed that greater neighborhood disadvantage was associated with lower RSI-RND in the left superior longitudinal fasciculus (β = -0.055; 95% CI, -0.081 to -0.028) and forceps major (β = -0.040; 95% CI, -0.067 to -0.013). Lower parental educational attainment was associated with lower RSI-RND in the bilateral superior longitudinal fasciculus (eg, right hemisphere: β = 0.053; 95% CI, 0.025-0.080) and bilateral corticospinal or pyramidal tract (eg, right hemisphere: β = 0.042; 95% CI, 0.015-0.069). Structural equation models revealed that lower cognitive performance (eg, lower total cognition score and higher neighborhood disadvantage: β = -0.012; 95% CI, -0.016 to -0.009) and greater obesity (eg, higher BMI and higher neighborhood disadvantage: β = -0.004; 95% CI, -0.006 to -0.001) partially accounted for the associations between SES and RSI-RND. Lower household income was associated with higher RSI-RNI in most tracts (eg, right inferior longitudinal fasciculus: β = -0.042 [95% CI, -0.073 to -0.012]; right anterior thalamic radiations: β = -0.045 [95% CI, -0.075 to -0.014]), and greater neighborhood disadvantage had similar associations in primarily frontolimbic tracts (eg, right fornix: β = 0.046 [95% CI, 0.019-0.074]; right anterior thalamic radiations: β = 0.045 [95% CI, 0.018-0.072]). Lower parental educational attainment was associated with higher RSI-RNI in the forceps major (β = -0.048; 95% CI, -0.077 to -0.020). Greater obesity partially accounted for these SES associations with RSI-RNI (eg, higher BMI and higher neighborhood disadvantage: β = 0.015; 95% CI, 0.011-0.020). Findings were robust in sensitivity analyses and were corroborated using diffusion tensor imaging.

Conclusions and Relevance

In this cross-sectional study, both neighborhood and household contexts were associated with white matter development in children, and findings suggested that obesity and cognitive performance were possible mediators in these associations. Future research on children's brain health may benefit from considering these factors from multiple socioeconomic perspectives.

Obesity is associated with decreased gray matter volume in children: a longitudinal study

Childhood obesity has become a global health problem. Previous studies showed that childhood obesity is associated with brain structural differences relative to controls. However, few studies have been performed with longitudinal evaluations of brain structural developmental trajectories in childhood obesity. We employed voxel-based morphometry (VBM) analysis to assess gray matter (GM) volume at baseline and 2-year follow-up in 258 obese children (OB) and 265 normal weight children (NW), recruited as part of the National Institutes of Health Adolescent Brain and Cognitive Development study. Significant group × time effects on GM volume were observed in the prefrontal lobe, thalamus, right precentral gyrus, caudate, and parahippocampal gyrus/amygdala. OB compared with NW had greater reductions in GM volume in these regions over the 2-year period. Body mass index (BMI) was negatively correlated with GM volume in prefrontal lobe and with matrix reasoning ability at baseline and 2-year follow-up. In OB, Picture Test was positively correlated with GM volume in the left orbital region of the inferior frontal gyrus (OFCinf_L) at baseline and was negatively correlated with reductions in OFCinf_L volume (2-year follow-up vs. baseline). These findings indicate that childhood obesity is associated with GM volume reduction in regions involved with reward evaluation, executive function, and cognitive performance.

Associations between socioeconomic status and white matter microstructure in children: indirect effects via obesity and cognition

Importance

Both neighborhood and household socioeconomic disadvantage relate to negative health outcomes and altered brain structure in children. It is unclear whether such findings extend to white matter development, and via what mechanisms socioeconomic status (SES) influences the brain.

Objective

To test independent associations between neighborhood and household SES indicators and white matter microstructure in children, and examine whether body mass index and cognitive function (a proxy of environmental cognitive/sensory stimulation) may plausibly mediate these associations.

Design

This cross-sectional study used baseline data from the Adolescent Brain Cognitive Development (ABCD) Study, an ongoing 10-year cohort study tracking child health.

Setting

School-based recruitment at 21 U.S. sites.

Participants

Children aged 9 to 11 years and their parents/caregivers completed baseline assessments between October 1 ^st , 2016 and October 31 ^st , 2018. Data analysis was conducted from July to December 2022.

Exposures

Neighborhood disadvantage was derived from area deprivation indices at primary residence. Household SES indicators were total income and the highest parental education attainment.

Main Outcomes and Measures

Thirty-one major white matter tracts were segmented from diffusion-weighted images. The Restriction Spectrum Imaging (RSI) model was implemented to measure restricted normalized directional (RND; reflecting oriented myelin organization) and isotropic (RNI; reflecting glial/neuronal cell bodies) diffusion in each tract. Obesity-related measures were body mass index (BMI), BMI z -scores, and waist circumference, and cognitive performance was assessed using the NIH Toolbox Cognition Battery. Linear mixed-effects models tested the associations between SES indicators and scanner-harmonized RSI metrics. Structural equation models examined indirect effects of obesity and cognitive performance in the significant associations between SES and white mater microstructure summary principal components. Analyses were adjusted for age, sex, pubertal development stage, intracranial volume, and head motion.

Results

The analytical sample included 8842 children (4299 [48.6%] girls; mean age [SD], 9.9 [0.7] years). Greater neighborhood disadvantage and lower parental education were independently associated with lower RSI-RND in forceps major and corticospinal/pyramidal tracts, and had overlapping associations in the superior longitudinal fasciculus. Lower cognition scores and greater obesity-related measures partially accounted for these SES associations with RSI-RND. Lower household income was related to higher RSI-RNI in almost every tract, and greater neighborhood disadvantage had similar effects in primarily frontolimbic tracts. Lower parental education was uniquely linked to higher RSI-RNI in forceps major. Greater obesity-related measures partially accounted for these SES associations with RSI-RNI. Findings were robust in sensitivity analyses and mostly corroborated using traditional diffusion tensor imaging (DTI).

Conclusions and Relevance

These cross-sectional results demonstrate that both neighborhood and household contexts are relevant to white matter development in children, and suggest cognitive performance and obesity as possible pathways of influence. Interventions targeting obesity reduction and improving cognition from multiple socioeconomic angles may ameliorate brain health in low-SES children.

Key Points

Question: Are neighborhood and household socioeconomic levels associated with children’s brain white matter microstructure, and if so, do obesity and cognitive performance (reflecting environmental stimulation) mediate the associations?Findings: In a cohort of 8842 children, higher neighborhood disadvantage, lower household income, and lower parental education had independent and overlapping associations with lower restricted directional diffusion and greater restricted isotropic diffusion in white matter. Greater body mass index and poorer cognitive performance partially mediated these associations.Meaning: Both neighborhood and household poverty may contribute to altered white matter development in children. These effects may be partially explained by obesity incidence and poorer cognitive performance.

Los efectos neurofisiológicos de la actividad física en los niños: revisión sistemática

La práctica de actividad física regular proporciona varios beneficios relacionados principalmente con la mejora de la salud y la calidad de vida, así como con el control de los factores de riesgo de enfermedades, un tema ampliamente reconocido en la actualidad. Sin embargo, estudios recientes han demostrado que la relación entre actividad física y cognición está permitiendo grandes avances y resultados positivos. En el presente trabajo y mediante una revisión sistemática, se recopila la evidencia actual que estable la causalidad sobre los cambios neurofisiológicos en la estructura cerebral de niños sanos y con patologías. Un total de 23 estudios fueron seleccionados y analizados mediante los que se pudo concluir que existe una asociación beneficiosa entre la actividad física a largo plazo y los cambios en las funciones neurofisiológicas.

Effect of Physical Exercise in Real-World Settings on Executive Function of Typical Children and Adolescents: A Systematic Review

OBJECTIVE

The aim of this paper is to provide a systematic review of research on physical exercise in real-world settings on executive function of typical children and adolescents.

METHODS

The CNKI, WOS, PubMed, ScienceDirect, and SPORTDiscus databases were searched by computer. Two researchers independently screened the literature, extracted data, and evaluated the risk of bias in the included literature. Statistical analysis was performed using frequency and percentage and the χ² test.

RESULTS

A total of 49 articles was included. Acute (moderate intensity lasting 30-50 min) and long-term (interventions of moderate intensity of 30-50 min at least 3 times a week for 17 weeks or more) physical exercises in real-world settings have positive intervention effects on executive function. Furthermore, for acute interventions, closed skills are more efficient for inhibitory control, open skills are more efficient for working memory and cognitive flexibility, and open-continuous and closed-sequential skills are the most efficient; long-term interventions with open skills, sequential skills, and open-sequential skills are more effective.

CONCLUSION

Physical exercise in real-world settings has a good promotion effect on typical children and adolescents, and motor skills with open and/or sequential attributes are more helpful in improving executive function.

Associations between 24-h Movement Behavior and Internet Addiction in Adolescents: A Cross-Sectional Study

OBJECTIVE

This study aimed to explore the relationship between 24-h activity behavior and Chinese adolescents' Internet addiction.

METHODS

A survey of 2045 adolescents (56.5% boys) was conducted, and adolescents' 24-h movement behavior and Internet addiction were measured via a questionnaire. Descriptive statistics were used to analyze the basic situation of the respondents; chi-square analysis was used to compare gender differences, and logistic regression was used to analyze the relationship between 24-h exercise guide entries and Internet addiction.

RESULTS

From the number of 24-h movement behavior guides, 25.3% of the children did not meet the recommended amount of any kind of activity behavior guide, while 50.4% and 21.7% of the children reached the recommended amount of one and two activity behavior guidelines, respectively; only 3.2% of the children met the recommended amount of all three activity behavior guidelines. Adolescents who did not meet the recommended 24-h activity behavior guidelines were more likely to have Internet addiction (OR = 8.46, 95 CI = 3.06-23.36), and were more likely to have one item (OR = 4.50, 95 CI = 1.64-12.39) or two items (OR = 3.12, 95 CI = 1.11-8.74).

CONCLUSIONS

Physical activity, static behavior, and sleep may all have a greater impact on adolescents' Internet addiction, among which physical activity has a greater impact on adolescents' Internet addiction. Different combinations of 24-h movement behavior have different effects on adolescents' Internet addiction.

Effects of exercise types on white matter microstructure in late midlife adults: Preliminary results from a diffusion tensor imaging study

Higher aerobic fitness during late midlife is associated with higher white matter (WM) microstructure. Compared with individuals engaged in irregular exercise, those who engage in regular aerobic exercise show higher fractional anisotropy (FA), a diffusion tenor imaging (DTI) measure that provides an index of WM microstructural integrity. However, whether other types of exercise, such as Tai Chi, can also facilitate WM changes in adults during late midlife remains unknown. The present study compares two types of exercise, Tai Chi and walking, with a sedentary control group, in order to examine the effects of exercise on WM microstructure and determine the regional specificity of WM differences. Thirty-six healthy adults between the ages of 55 and 65 years participated in the study. Based on the participants’ exercise habits, they were allocated into three groups: Tai Chi, walking, or sedentary control. All participants were required to complete physical fitness measurements and completed magnetic reasoning imaging (MRI) scans. Our results revealed that the Tai Chi group exhibited a higher FA value in the left cerebral peduncle, compared to the sedentary control group. We also observed that both the Tai Chi and walking groups exhibited higher FA values in the right uncinate fasciculus and the left external capsule, in comparison to the sedentary control group. Increased FA values in these regions was positively correlated with higher levels of physical fitness measurements (i.e., peak oxygen uptake [VO2peak], muscular endurance/number of push-up, agility, power). These findings collectively suggest that regular exercise is associated with improved WM microstructural integrity, regardless of the exercise type, which could guide the development and application of future prevention and intervention strategies designed to address age-related cognitive impairments during late midlife.

Physical activity and exercise alter cognitive abilities, and brain structure and activity in obese children

The prevalence of childhood obesity is increasing to such an extent that it has become a major global public health problem in the 21st century. Obesity alters children’s brain structure and activity and impairs their cognitive abilities. On the basis of these findings, it is necessary for educational and healthcare institutions to combat childhood obesity through preventive and therapeutic strategies. In general, exercise and physical activity are considered common but effective methods for improving physical, psychological, and brain health across the life span. Therefore, this review article mainly focuses on existing neuroimaging studies that have used magnetic resonance imaging (MRI), and functional magnetic resonance imaging (fMRI)to assess children’s brain anatomy and neural activity. We intended to explore the roles of physical activity and exercise in modulating the associations among childhood obesity, cognitive abilities, and the structure and activity of the brain.

Effects of an Exercise Program on Brain Health Outcomes for Children With Overweight or Obesity: The ActiveBrains Randomized Clinical Trial

IMPORTANCE

Pediatric overweight and obesity are highly prevalent across the world, with implications for poorer cognitive and brain health. Exercise might potentially attenuate these adverse consequences.

OBJECTIVES

To investigate the effects of an exercise program on brain health indicators, including intelligence, executive function, academic performance, and brain outcomes, among children with overweight or obesity and to explore potential mediators and moderators of the main effects of exercise.

DESIGN, SETTING, AND PARTICIPANTS

All preexercise and postexercise data for this 20-week randomized clinical trial of 109 children aged 8 to 11 years with overweight or obesity were collected from November 21, 2014, to June 30, 2016, with neuroimaging data processing and analyses conducted between June 1, 2017, and December 20, 2021. All 109 children were included in the intention-to-treat analyses; 90 children (82.6%) completed the postexercise evaluation and attended 70% or more of the recommended exercise sessions and were included in per-protocol analyses.

INTERVENTIONS

All participants received lifestyle recommendations. The control group continued their usual routines, whereas the exercise group attended a minimum of 3 supervised 90-minute sessions per week in an out-of-school setting.

MAIN OUTCOMES AND MEASURES

Intelligence, executive function (cognitive flexibility, inhibition, and working memory), and academic performance were assessed with standardized tests, and hippocampal volume was measured with magnetic resonance imaging.

RESULTS

The 109 participants included 45 girls (41.3%); participants had a mean (SD) body mass index of 26.8 (3.6) and a mean (SD) age of 10.0 (1.1) years at baseline. In per-protocol analyses, the exercise intervention improved crystallized intelligence, with the exercise group improving from before exercise to after exercise (mean z score, 0.62 [95% CI, 0.44-0.80]) compared with the control group (mean z score, -0.10 [95% CI, -0.28 to 0.09]; difference between groups, 0.72 SDs [95% CI, 0.46-0.97]; P < .001). Total intelligence also improved significantly more in the exercise group (mean z score, 0.69 [95% CI, 0.48-0.89]) than in the control group (mean z score, 0.07 [95% CI, -0.14 to 0.28]; difference between groups, 0.62 SDs [95% CI, 0.31-0.91]; P < .001). Exercise also positively affected a composite score of cognitive flexibility (mean z score: exercise group, 0.25 [95% CI, 0.05-0.44]; control group, -0.17 [95% CI, -0.39 to 0.04]; difference between groups, 0.42 SDs [95% CI, 0.13-0.71]; P = .005). These main effects were consistent in intention-to-treat analyses and after multiple-testing correction. There was a positive, small-magnitude effect of exercise on total academic performance (mean z score: exercise group, 0.31 [95% CI, 0.18-0.44]; control group, 0.10 [95% CI, -0.04 to 0.24]; difference between groups, 0.21 SDs [95% CI, 0.01-0.40]; P = .03), which was partially mediated by cognitive flexibility. Inhibition, working memory, hippocampal volume, and other brain magnetic resonance imaging outcomes studied were not affected by the exercise program. The intervention increased cardiorespiratory fitness performance as indicated by longer treadmill time to exhaustion (mean z score: exercise group, 0.54 [95% CI, 0.27-0.82]; control group, 0.13 [95% CI, -0.16 to 0.41]; difference between groups, 0.42 SDs [95% CI, 0.01-0.82]; P = .04), and these changes in fitness mediated some of the effects (small percentage of mediation [approximately 10%-20%]). The effects of exercise were overall consistent across the moderators tested, except for larger improvements in intelligence among boys compared with girls.

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, exercise positively affected intelligence and cognitive flexibility during development among children with overweight or obesity. However, the structural and functional brain changes responsible for these improvements were not identified.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02295072.

Effects of aerobic versus cognitively demanding exercise interventions on brain structure and function in healthy children-Results from a cluster randomized controlled trial

The beneficial effects of physical activity on neurocognitive functioning in children are considered to be facilitated by physical activity-induced changes in brain structure and functioning. In this study, we examined the effects of two 14-week school-based exercise interventions in healthy children on white matter microstructure and brain activity in resting-state networks (RSNs) and whether changes in white matter microstructure and RSN activity mediate the effects of the exercise interventions on neurocognitive functioning. A total of 93 children were included in this study (51% girls, mean age 9.13 years). The exercise interventions consisted of four physical education lessons per week, focusing on either aerobic or cognitively demanding exercise and were compared with a control group that followed their regular physical education program of two lessons per week. White matter microstructure was assessed using diffusion tensor imaging in combination with tract-based spatial statistics. Independent component analysis was performed on resting-state data to identify RSNs. Furthermore, neurocognitive functioning (information processing and attention, working memory, motor response inhibition, interference control) was assessed by a set of computerized tasks. Results indicated no Group × Time effects on white matter microstructure or RSN activity, indicating no effects of the exercise interventions on these aspects of brain structure and function. Likewise, no Group × Time effects were found for neurocognitive performance. This study indicated that 14-week school-based interventions regarding neither aerobic exercise nor cognitive-demanding exercise interventions influence brain structure and brain function in healthy children. This study was registered in the Netherlands Trial Register (NTR5341).

Mediators between physical activity and academic achievement: A systematic review

BACKGROUND

Research has suggested the beneficial effects of physical activity (PA) on academic achievement (AA). However, the mechanisms underlying this influence remain unclear. Some proposed mechanisms include physiological, cognitive, psychological, and behavioral paths. This study aimed to analyze mediators between PA and AA in children and adolescents.

METHODS

Systematic search in Medline, SPORTDiscuss, PsycInfo, Scopus, and Web of Science for observational and experimental studies, published up to March 2021.

RESULTS

Twenty-eight studies (75237 participants, aged 4-16) were included. The designs of these studies were: 21 studies cross-sectional, 5 longitudinal, and 2 experimental. Eight out of nine studies analyzing fitness as a mediator reported positive results, and one reported null finding. Adiposity was a significant mediator in one study, in two only in girls, and two reported null results. Cognition as a mediator was supported by four studies, whereas two reported null results. Regarding mental well-being, 10 out of 14 studies reported positive effects, and one out of five behavioral studies found positive results. Although studies were too sparse to draw conclusions, overall, the results indicated that self-esteem, self-image, self-efficacy, stress, and health behaviors might be potential mediators in the relationship between PA and AA. All studies were rated as medium-high quality.

CONCLUSION

Overall, the available evidence seems to suggest that cardiorespiratory fitness, cognition, mental well-being, and exercise-related behaviors play some role as mediators of the relationship between PA and AA. However, the cross-sectional nature of most of the reviewed studies prevents us from making any statement in terms of causal paths. Thus, well-designed follow-up and randomized controlled studies aimed not only to tests the effect of PA in AA, but also to examine the influence of mediators are required.

Independent and combined associations between multiple lifestyle behaviours and academic grades of inner urban and peri-urban high school students: a cross-sectional study in Chongqing, China

OBJECTIVES

This study aims to assess the independent and combined associations between multiple lifestyle behaviours and academic grades of inner urban high school students (IUHSSs) and peri-urban high school students (PUHSSs).

DESIGN

A cross-sectional study was conducted.

PARTICIPANTS

There are 1481 high school students (49.9% boys) in this study, who were enrolled from one inner urban and two peri-urban schools in Chongqing, China.

OUTCOME MEASURES

Academic grades were assessed based on the students' self-reported grade ranking in the last cumulative examination.

RESULTS

In IUHSSs and PUHSSs, high frequency of sugar-sweetened beverage consumption was unlikely to obtain high academic grades (OR 0.56, 95% CI 0.32 to 0.99 and 0.63, 95% CI 0.42 to 0.96), respectively). Among IUHSSs, meeting the recommendations for weekday screen time and egg consumption (OR 1.57, 95% CI 1.06 to 2.34 and 1.60, 95% CI 1.04 to 2.47, respectively) and high frequency of fruit consumption (1.67, 95% CI 1.11 to 2.50) were significantly associated with high academic grades; meeting the recommendation for weekday sleep duration was unlikely to obtain high academic grades (0.46, 95% CI 0.21 to 0.98). Among PUHSSs, meeting the recommendations for weekend sleep duration (1.40, 95% CI 1.02 to 1.93) and eating dinner regularly (1.55, 95% CI 1.01 to 2.37) had significant associations with high academic grades. No significant associations were found between physical activity and academic grades in both IUHSSs and PUHSSs (p>0.05). Moreover, IUHSSs with 9-13 healthy lifestyle behaviours were 3.25 times more likely to achieve high academic grades than IUHSSs with 1-6 healthy lifestyle behaviours (3.25, 95% CI 1.96 to 5.40). No significant associations were found in the combined associations between multiple lifestyle behaviours and academic grades among PUHSSs (p>0.05).

CONCLUSIONS

Correlations were observed between lifestyle behaviours and academic grades among high school students, and cumulative associations between multiple healthy lifestyle behaviours and academic outcomes appear to be stronger than the independent associations. These findings are particularly applicable to IUHSSs.

The Role of Chronic Physical Activity in Alleviating the Detrimental Relationship of Childhood Obesity on Brain and Cognition

Childhood obesity and its negative relation with children’s brain health has become a growing health concern. Over the last decade, literature has indicated that physical activity attenuates cognitive impairment associated with obesity and excess adiposity in children. However, there is no comprehensive review that considers the extent to which these factors affect different domains of cognition. This narrative review comprehensively summarizes behavioral, neuroimaging, and neuroelectric findings associated with chronic physical activity and fitness on brain and cognition in childhood obesity. Based on the literature reviewed, increased adiposity has a demonstrated relationship with neurocognitive health via mechanisms triggered by central inflammation and insulin resistance, with the most pronounced decrements observed for cognitive domains that are prefrontal- and hippocampal-dependent. Fortunately, physical activity, especially interventions enhancing aerobic fitness and motor coordination, have demonstrated efficacy for attenuating the negative effects of obesity across different subdomains of structural and functional brain imaging, cognition, and multiple academic outcomes in children with overweight or obesity. Such mitigating effects may be accounted for by attenuated central inflammation, improved insulin sensitivity, and increased expression of neurotrophic factors. Lastly, individual differences appear to play a role in this relationship, as the manipulation of physical activity characteristics, the employment of a wide array of cognitive and academic measures, the inclusion of different adiposity measures that are sensitive to neurocognitive function, and the utilization of an inter-disciplinary approach have been found to influence the relationship between physical activity and excess adiposity on brain and cognition.

Physical Activity, Fitness, and Executive Functions in Youth: Effects, Moderators, and Mechanisms

Over the last decade, a growing body of research has examined the link between physical activity, fitness, and cognitive function in children and adolescents. Physical activity experimental research conducted with children and adolescents has identified selectively greater effects for tasks requiring higher order executive functions. As such, the primary aim of our chapter is to provide an overview of findings from systematic reviews and meta-analyses that have examined the effects of physical activity on measures of executive function in child and adolescent populations. We begin our chapter with definitions of key concepts associated with physical activity, fitness and cognitive function. We then provide a synthesis of systematic reviews and meta-analyses that have examined the acute and chronic effect of physical activity on EFs. Following this, we discuss the quantitative (e.g., time, intensity) and qualitative (e.g., type) characteristics of physical activity that may moderate effects. The next section focuses on the neurobiological, psychosocial and behavioral mechanisms responsible for the effect of physical activity on executive functions. We conclude by highlighting the limitations of the existing evidence base and providing recommendations for future research.

The relationship between white matter microstructure, cardiovascular fitness, gross motor skills, and neurocognitive functioning in children

Recent evidence indicates that both cardiovascular fitness and gross motor skill performance are related to enhanced neurocognitive functioning in children by influencing brain structure and functioning. This study investigates the role of white matter microstructure in the relationship of both cardiovascular fitness and gross motor skills with neurocognitive functioning in healthy children. In total 92 children (mean age 9.1 years, range 8.0-10.7) were included in this study. Cardiovascular fitness and gross motor skill performance were assessed using performance-based tests. Neurocognitive functioning was assessed using computerized tests (working memory, inhibition, interference control, information processing, and attention). Diffusion tensor imaging was used in combination with tract-based spatial statistics to assess white matter microstructure as defined by fractional anisotropy (FA), axial and radial diffusivity (AD, RD). The results revealed positive associations of both cardiovascular fitness and gross motor skills with neurocognitive functioning. Information processing and motor response inhibition were associated with FA in a cluster located in the corpus callosum. Within this cluster, higher cardiovascular fitness and better gross motor skills were both associated with greater FA, greater AD, and lower RD. No mediating role was found for FA in the relationship of both cardiovascular fitness and gross motor skills with neurocognitive functioning. The results indicate that cardiovascular fitness and gross motor skills are related to neurocognitive functioning as well as white matter microstructure in children. However, this study provides no evidence for a mediating role of white matter microstructure in these relationships.

Associations between neighborhood greenspace and brain imaging measures in non-demented older adults: the Cardiovascular Health Study

PURPOSE

Greater neighborhood greenspace has been associated with brain health, including better cognition and lower odds of Alzheimer's disease in older adults. We investigated associations between neighborhood greenspace and brain-based magnetic resonance imaging (MRI) measures and potential effect modification by sex or apolipoprotein E genotype (APOE), a risk factor for Alzheimer's disease.

METHODS

We obtained a sample of non-demented participants 65 years or older (n = 1125) from the longitudinal, population-based Cardiovascular Health Study (CHS). Greenspace data were derived from the National Land Cover Dataset. Adjusted multivariable linear regression estimated associations between neighborhood greenspace five years prior to the MRI and left and right hippocampal volume and 10-point grades of ventricular size and burden of white matter hyperintensity. Interaction terms tested effect modification by APOE genotype and sex. CHS data (1989-1999) were obtained/analyzed in 2020.

RESULTS

Participants were on average 79 years old [standard deviation (SD) = 4], 58% were female, and 11% were non-white race. Mean neighborhood greenspace was 38% (SD = 28%). Greater proportion of greenspace in the neighborhood five years before MRI was borderline associated with lower ventricle grade (estimate: - 0.30; 95% confidence interval: - 0.61, 0.00). We observed no associations between greenspace and the other MRI outcome measures and no evidence of effect modification by APOE genotype and sex.

CONCLUSION

This study suggests a possible association between greater greenspace and less ventricular enlargement, a measure reflecting global brain atrophy. If confirmed in other longitudinal cohort studies, interventions and policies to improve community greenspaces may help to maintain brain health in older age.

Influence of Aerobic Fitness on White Matter Integrity and Inhibitory Control in Early Adulthood: A 9-Week Exercise Intervention

Previous cross-sectional studies have related aerobic fitness to inhibitory control and white matter (WM) microstructure in young adults, but there is no longitudinal study to confirm whether these relationships exist. We carried out a longitudinal study comparing aerobic fitness, inhibitory control, and WM integrity across time points, before versus after completing an exercise intervention in young adults (18–20 years old) relative to a control group. The exercise group (n = 35) participated in a 9-week exercise protocol, while the control group (n = 24) did not receive any regular exercise training. Behavioral data and diffusion tensor imaging (DTI) data were collected prior to and following the intervention. After the exercise intervention, aerobic fitness and inhibitory control performance were significantly improved for the exercise group, but not for the control group. Analyses of variance (ANOVA) of the DTI data demonstrated significantly increased fractional anisotropy (FA) in the right corticospinal tract and significantly decreased FA in the left superior fronto-occipital fasciculus in the exercise group after the intervention versus before. The enhanced aerobic fitness induced by exercise was associated with better inhibitory control performance in the incongruent condition and lower FA in the Left superior fronto-occipital fasciculus (SFOF). Regression analysis of a mediation model did not support Left SFOF FA as a mediator of the relationship between improvements in aerobic fitness and inhibitory control. The present data provide new evidence of the relationship between exercise-induced changes in aerobic fitness, WM integrity, and inhibitory control in early adulthood. Longer-duration intervention studies with larger study cohorts are needed to confirm and further explore the findings obtained in this study.

Prevalence of Internet Addiction and Its Relationship With Combinations of Physical Activity and Screen-Based Sedentary Behavior Among Adolescents in China

BACKGROUND

Given the widespread prevalence and serious nature of Internet addiction (IA), this study aimed to estimate the prevalence of IA and assess the relationships between IA and combinations of physical activity (PA) and screen-based sedentary behavior (SB) among adolescents in China.

METHODS

This cross-sectional study surveyed 31,954 adolescents in grades 7 to 12 in Beijing. IA, PA, screen-based SB, and other information were obtained from a self-administrated questionnaire. The chi-square test and mixed-effects logistic regression model were applied to estimate the relationship between IA and combinations of PA and screen-based SB.

RESULTS

6.2% of the surveyed adolescents reported IA and the prevalence of low PA/high screen-based SB, high PA/high screen-based SB, low PA/low screen-based SB, and high PA/low screen-based SB were 53.7%, 19.5%, 18.8%, and 8.0%, respectively. Mixed-effects logistic regression analysis showed that adolescents with low PA/high screen-based SB were 1.99 (95% confidence interval, 1.62-2.44, P < .001) times more likely to prefer IA than those with high PA/low screen-based SB.

CONCLUSIONS

The prevalence of IA among Chinese adolescents is still high. Intervention programs like maintaining sufficient PA and reducing screen-based SB might contribute to reducing their IA.

Child physical activity as a modifier of the relationship between prenatal exposure to maternal overweight/obesity and neurocognitive outcomes in offspring

BACKGROUND/OBJECTIVES

With rising obesity rates among pregnant women, more children are exposed in utero to maternal obesity. In prior epidemiological studies, exposure to maternal obesity was associated with lower intelligence quotient (IQ) scores and worse cognitive abilities in offspring. Further studies have shown that offspring exposed to maternal obesity, exhibit differences in the white matter microstructure properties, fractional anisotropy (FA) and mean diffusivity (MD). In contrast, physical activity was shown to improve cognition and white matter microstructure during childhood. We examined if child physical activity levels modify the relationship between prenatal exposure to maternal obesity with IQ and white matter microstructure in offspring.

SUBJECTS/METHODS

One hundred children (59% girls) age 7-11 years underwent brain magnetic resonance imaging and IQ testing. Maternal pre-pregnancy BMI was abstracted from electronic medical records. White matter was assessed using diffusion tensor imaging with the measures, global FA, MD. The 3-day physical activity recall was used to measure moderate-to-vigorous physical activity and vigorous physical activity (VPA). Linear regression was used to test for interactions between prenatal exposure to maternal overweight/obesity and child PA levels on child IQ and global FA/MD.

RESULTS

The relationship between prenatal exposure to maternal overweight/obesity and child IQ and global FA varied by child VPA levels. Children exposed to mothers with overweight/obesity who engaged in more VPA had higher IQ scores and global FA compared to exposed children who engaged in less VPA. Associations were independent of child age, sex, BMI Z-score and socioeconomic status. Children born to normal-weight mothers did not differ in either IQ or global FA by time in VPA.

CONCLUSIONS

Our findings support findings in rodent models and suggest that VPA during childhood modifies the relationship between prenatal exposure to maternal obesity and child IQ and white matter microstructure.

Six-Minute Walking Test Performance Relates to Neurocognitive Abilities in Preschoolers

This study investigated the relationship between six-minute walking test (6MWT) distance walked and preschool-aged children’s academic abilities, and behavioral and event-related potentials (ERP) indices of cognitive control. There were 59 children (25 females; age: 5.0 ± 0.6 years) who completed a 6MWT (mean distance: 449.6 ± 82.0 m) to estimate cardiorespiratory fitness. The Woodcock Johnson Early Cognitive and Academic Development Test evaluated academic abilities. A modified Eriksen flanker, hearts and flowers task, and auditory oddball task eliciting ERPs (N2, P3) assessed cognitive control. After adjusting for adiposity, diet, and demographics, linear regressions resulted in positive relationships between 6MWT distance and General Intellectual Ability (β = 0.25, Adj R² = 0.04, p = 0.04) and Expressive Language (β = 0.30, Adj R² = 0.13, p = 0.02). 6MWT distance was positively correlated with congruent accuracy (β = 0.29, Adj R² = 0.18, p < 0.01) and negatively with incongruent reaction time (β = −0.26, Adj R² = 0.05, p = 0.04) during the flanker task, and positively with homogeneous (β = 0.23, Adj R² = 0.21, p = 0.04) and heterogeneous (β = 0.26, Adj R² = 0.40, p = 0.02) accuracy on the hearts and flowers task. Higher fit children showed faster N2 latencies and greater P3 amplitudes to target stimuli; however, these were at the trend level following the adjustment of covariates. These findings indicate that the positive influence of cardiorespiratory fitness on cognitive function is evident in 4–6-year-olds.

Effects of physical activity interventions on cognitive performance of overweight or obese children and adolescents: a systematic review and meta-analysis

BACKGROUND

Physical activity (PA) and obesity were linked with poor cognition. Our study assessed PA interventions could improve domain-specific cognition among overweight/obese youth.

METHODS

Systematically searched PubMed to identify relevant studies published up to October 2019. Standardized mean differences (SMD) of pre-post intervention were calculated in meta-analysis. The level of study heterogeneity represented by I² was interpreted as small (I² ≤ 25%), moderate (25% < I² ≤ 50%), substantial (50% < I² ≤ 75%), or considerable (I² > 75%).

RESULTS

Seventeen studies met the inclusion criteria; eight were included in the meta-analysis. Meta-analysis revealed that PA interventions improved core executive functions (core-EFs) (SMD = 0.301; 95% CI = 0.002-0.600; I²% = 80.6%) and non-EFs (SMD = 0.159; 95% CI = 0.029-0.289; I²% = 0.0%), but not metacognition and academic performance. Core-EFs benefited from enriched PA (SMD = 0.535; 95% CI = 0.020-1.051; I²% = 72.0%) and enhanced and enriched PA (SMD = 1.005; 95% CI = 0.017-1.993; I²% = 90.8%) interventions, while the non-EFs benefited more from enhanced PA (SMD = 0.166; 95% CI = 0.018-0.314; I²% = 0.0%). Interventions with a favorable effect on adiposity measures resulted in a significantly greater improvement in core-EFs (SMD = 0.438; 95% CI = 0.047-0.829; I²% = 58.8%) than those with no effects.

CONCLUSIONS

PA interventions can improve several domains of cognition, especially core-EFs and non-EFs, and the effects are affected by PA characteristics among overweight and obese youth.

IMPACT

Our study is the first to quantify the effect of PA interventions on CP among overweight or obese children and adolescents. Physical activity interventions positively affect cognitive performance, especially core executive functions (core-EFs) and non-EFs. Physical activity interventions seem to not positively affect metacognition (higher-level EFs and cognitive life skills) and academic performance. Physical task characteristics could influence the effect of chronic exercise on cognitive performance. Short-term physical activity programs may be particularly beneficial to affect core-EFs.

Moderate Intensity Exercise in Pre-manifest Huntington's Disease: Results of a 6 months Trial

BACKGROUND

While it has been shown that aerobic exercise interventions are well tolerated in participants with the Huntington disease (HD) gene mutation, no study to date has tested whether an aerobic exercise intervention benefits brain structure and function in pre-manifest HD.

OBJECTIVE

In this study we utilized magnetic resonance (MR) imaging techniques to assess the efficacy of moderate-to-vigorous exercise treatment relative to active stretching and toning control.

METHODS

Forty pre-manifest participants with confirmed HD gene expansion were recruited into a two-arm intervention study that included a moderate-to-vigorous intensity home-based walking exercise intervention (N=34) and an active stretching and toning control intervention (N=6). Participants were assessed at baseline and after 26 weeks in one of the two study arms.

RESULTS

25 of the 34 (74%) participants assigned to the moderate-to-vigorous intensity group completed the intervention while 4 of the 6 (67%) participants in the stretching and toning intervention completed the study. The primary analyses compared the two arms of the study and found no statistical differences between the groups. Both groups were found to have improved their cardiorespiratory fitness as assessed by maximal oxygen uptake (VO₂max). A secondary analysis combined the two arms of the study and there was a significant relationship (p<0.05) between change in VO₂max and change in brain structure.

CONCLUSIONS

Though this study did not show efficacy for the exercise intervention, secondary results suggest that aerobic exercise interventions increasing cardiorespiratory fitness may be a potential way to slow progression in pre-manifest HD.

Physical Activity, Sedentary Behavior, and White Matter Microstructure in Children with Overweight or Obesity

PURPOSE

This study aimed to investigate the associations of objectively measured and self-reported physical activity (PA) and sedentary behavior with white matter microstructure in children with overweight or obesity.

METHODS

In a sample of 103 participants (age, 10.02 ± 1.15 yr; 42 girls) from the ActiveBrains project, we assessed PA and sedentary behavior using accelerometers (GT3X+; ActiGraph, Pensacola, FL), and the Youth Activity Profile-Spain questionnaire. Objectively measured PA and sedentary behavior were classified into different intensities following the hip- and wrist-based cutoff points for the Euclidean Norm Minus One metric by Hildebrand et al., wrist-based cutoff points for counts metric by Chandler et al., and hip-based cutoff points for counts metric for Romanzini et al. and Evenson et al. Magnetic resonance imaging of white matter microstructure, fractional anisotropy (FA), and mean diffusivity (MD) were derived from diffusion tensor imaging. Linear regression models were used to examine the associations of objectively measured and self-reported PA and sedentary behavior with global and tract-specific FA and MD.

RESULTS

Self-reported total PA was positively associated with global FA (β = 0.236, P = 0.038), whereas watching television was negatively associated with global FA (β = -0.270, P = 0.014). In regard to the objective measures, using single regression models, light PA (β = 0.273, P = 0.016), moderate-to-vigorous PA (β = 0.257, P = 0.035), and total PA (β = 0.294, P = 0.013) were positively associated with global FA only when Hildebrand-Euclidean Norm Minus One hip cut points were used for analyses. Lastly, no association was found between PA and sedentary behavior and FA and MD within individual tracts.

CONCLUSIONS

Our results suggest that PA and watching television are related to white matter microstructure in children with overweight or obesity. However, longitudinal large-scale studies are needed to confirm and expand these findings.

Mini-Basketball Training Program Improves Social Communication and White Matter Integrity in Children with Autism

Impairments in social communication (SC) represent one of the core symptoms of autism spectrum disorder (ASD). While previous studies have demonstrated that exercise intervention improves SC in children with ASD, there is currently no neuroscientific evidence supporting its benefits. Therefore, we evaluated the outcomes of a long-term exercise intervention on SC and white matter integrity (WMI) in children with ASD, and further explored the neural mechanism of exercise intervention on SC in these children. Twenty-nine children aged 3–6 years with ASD were assigned to either exercise group (n = 15) or control group (n = 14). The exercise group received a scheduled mini-basketball training program (5 sessions per week, forty minutes per session) for 12 consecutive weeks, while the control group was instructed to maintain their daily activities. Groups were assessed before and after intervention on SC and WMI. SC scores were lower in the exercise group post-intervention. Compared with the control group, WMI of the exercise group showed higher fractional anisotropy in the body of corpus callosum, fornix, right cerebral peduncle, left posterior limb of internal capsule, right retrolenticular part of internal capsule, left anterior corona radiate and left superior fronto-occipital fasciculus; lower mean diffusivity in the left anterior corona radiate and the bilateral corticospinal tract. Furthermore, increased WMI was associated with lower scores on a measure of social cognition in the overall sample. This study is the first to provide evidence that exercise intervention improves SC and white matter integrity in children with autism.

Neurobiological evidence of longer-term physical activity interventions on mental health outcomes and cognition in young people: A systematic review of randomised controlled trials

OBJECTIVE

To investigate putative neurobiological mechanisms that link longer-term physical activity interventions to mental health and cognitive outcomes using randomised controlled trials in children, adolescents and young adults.

DATA SOURCES

A range of medical and psychological science electronic databases were searched (MEDLINE, EMBASE, Scopus, Web of Science, PsychINFO).

REVIEW METHODS

Original research studies were selected, data were extracted and quality was appraised.

RESULTS

Sixteen primary papers were included, ranging from healthy and community samples to subclinical and clinical populations across a variety of age ranges and using different neurobiological measures (e.g. magnetic resonance imaging, electroencephalography, cortisol, brain-derived neurotropic factor).

DISCUSSION

The majority of studies report improvement in mental health and cognition outcomes following longer-term physical activity interventions which coincide with neurobiological alterations, especially neuroimaging alterations in activation and electrophysiological parameters in frontal areas. Future research should include measures of pre-existing fitness and target those who would benefit the most from this type of intervention (e.g. those with a lower level of fitness and at risk for or with mental health problems).

Nucleus Accumbens Functional Connectivity with the Frontoparietal Network Predicts Subsequent Change in Body Mass Index for American Children

Background: Nucleus accumbens (NAc) is a brain structure with a well-established role in the brain reward processing system. Altered function of the NAc is shown to have a role in the development of food addiction and obesity. However, less is known about sex differences in the role of NAc function as a predictor of children’s change in body mass index (BMI) over time. Aim: We used the Adolescent Brain Cognitive Development data (version 2.01) to investigate sex differences in the predictive role of the NAc functional connectivity with the frontoparietal network on children’s BMI change over a one-year follow-up period. Methods: This 1-year longitudinal study successfully followed 3784 9–10-year-old children. Regression models were used to analyze the data. The predictor variable was NAc functional connectivity with the frontoparietal network measured using resting-state functional magnetic resonance imaging (fMRI). The primary outcome was BMI at the end of the 1-year follow up. Covariates included race, ethnicity, age, socioeconomic factors, and baseline BMI. Sex was the effect modifier. Results: NAc functional connectivity with the frontoparietal network was predictive of BMI changes over time. This association remained significant above and beyond all covariates. The above association, however, was only significant in female, not male children. Conclusion: The epidemiological observation that NAc functional connectivity is associated with BMI changes in children is an extension of well-controlled laboratory studies that have established the role of the NAc in the brain reward processing. More research is needed on sex differences in the brain regions that contribute to childhood obesity.

The Relationship Between Physical Activity and Inhibition in Children With and Without Motor Impairments

BACKGROUND

To examine the relationship between physical activity (PA) and inhibition in boys and girls with motor impairments compared with children with typical development.

METHODS

The participants were 58 (26 motor impairments and 32 typical development) children aged 7-12 years who met the inclusion criteria. PA was assessed using accelerometers for 7 consecutive days. The time spent in PA of different intensity levels (light, moderate, and vigorous) were analyzed for weekdays and weekends. Using a visuospatial attention paradigm, inhibition was evaluated by the difference in reaction time between invalid and valid cue conditions. Generalized linear mixed models were used to determine the associations of inhibition with PA and motor ability by sex.

RESULTS

Boys and children with typical development had shorter reaction times in inhibition than girls (P < .001) and children with motor impairments (P < .05), respectively. Motor ability (b = 189.98) and vigorous PA on weekdays (b = -43.18) were significant predictors of inhibition in girls only.

CONCLUSIONS

The results indicate a positive relationship between vigorous PA (on weekdays) and inhibition in children (girls), moderated by sex and motor ability. Effective interventions that promote vigorous PA for children both in and out of school should be designed to foster their executive function development.

The Roles of Physical Activity, Exercise, and Fitness in Promoting Resilience During Adolescence: Effects on Mental Well-Being and Brain Development

Adolescence is a critical yet vulnerable period for developing behaviors important for mental well-being. The existing literature suggests that physical activity (PA), exercise, and aerobic fitness promote well-being and reduce risk of mental health problems. In this review, we focus on PA, exercise, and fitness as modifiable resilience factors that may help promote self-regulation via strengthening of top-down control of bottom-up processes in the brain, thereby acting as a buffer against mental health problems during this period of vulnerability. First, we briefly review the link between PA, exercise, and aerobic fitness with mental well-being and reduced mental health problems in adolescence. Then we present how impairments in self-regulation, which involves top-down control to modulate bottom-up processes, are common across a wide range of mental health disorders. Finally, we use the extant neuroimaging literature to highlight how neural systems underlying top-down control continue to develop across adolescence, and propose that PA, exercise, and aerobic fitness may facilitate resilience through strengthening individual brain regions as well as large-scale neural circuits to improve emotional and behavioral regulation. Future neuroimaging studies assessing the effects of PA, exercise, and aerobic fitness at various developmental stages in each sex and studies considering the characteristics (e.g., frequency, intensity, type) and social context of PA and exercise are vital to better understand both macro- and microscale mechanisms by which these behaviors and attributes may facilitate mental health resilience during adolescent development.

The effects of physical activity on brain structure and neurophysiological functioning in children: A systematic review and meta-analysis

This study is the first to systematically review and quantify the effects of physical activity on brain structure and neurophysiological functioning in children. Electronic data bases were searched for relevant studies. Studies that met the following criteria were included: (1) used an RCT or cross-over design, (2) examined the effects of physical activity on brain structure and/or neurophysiological functioning, (3) included children (5-12 years old) (4) included a control group (RCTs) or control condition (cross-over trials). A total of 26 and 20 studies were included in the systematic review and meta-analysis, respectively, representing and accompanying 973 and 782 unique children. Main analyses were separated for short-term and long-term physical activity and for effects on brain structure and neurophysiological functioning with a distinction between children from healthy and clinical populations. We found evidence for significant beneficial effects of long-term physical activity on neurophysiological functioning (d = 0.39, p < 0.001). In addition, short-term physical activity may induce changes in neurophysiological functioning (d = 0.32, p = 0.044), although this evidence showed limited robustness. No meta-analytic evidence was found for positive effects on brain structure. The results underline the importance of physical activity for brain development in children.

Mini-Basketball Training Program Improves Physical Fitness and Social Communication in Preschool Children with Autism Spectrum Disorders

This investigation examined the effects of a 12-week mini-basketball training program (MBTP) on physical fitness and social communication in preschool children with autism spectrum disorders (ASD). The study applied a quasi-experimental design. Fifty-nine preschool children aged 3-6 years with ASD were assigned to either a MBTP group (n = 30) or a control group (n = 29). Participants in the MBTP group received a scheduled mini-basketball training program (5 sessions per week, forty minutes per session) for twelve consecutive weeks, while the control group was instructed to maintain their daily activities. The physical fitness test and the parent-reported Social Responsiveness Scale Second Edition (SRS-2) test were performed before and after the intervention. Results indicated that the 12-week MBTP facilitated performance in the physical fitness test, particularly in speed-agility and muscular strength abilities. Additionally, children in the MBTP group demonstrated improvement in SRS-2 performance in social awareness, social cognition, social communication, and autistic mannerisms, whereas no such changes were found in the control group. It may be concluded that the 12-week MBTP could improve physical fitness and social communication in preschool children with ASD, and thus the use of physical exercise intervention as a therapeutic tool for preschoolers with ASD is recommended.

A critical evaluation of systematic reviews assessing the effect of chronic physical activity on academic achievement, cognition and the brain in children and adolescents: a systematic review

BACKGROUND

International and national committees have started to evaluate the evidence for the effects of physical activity on neurocognitive health in childhood and adolescence to inform policy. Despite an increasing body of evidence, such reports have shown mixed conclusions. We aimed to critically evaluate and synthesise the evidence for the effects of chronic physical activity on academic achievement, cognitive performance and the brain in children and adolescents in order to guide future research and inform policy.

METHODS

MedLine, Embase, PsycINFO, Cochrane Library, Web of Science, and ERIC electronic databases were searched from inception to February 6th, 2019. Articles were considered eligible for inclusion if they were systematic reviews with or without meta-analysis, published in peer-reviewed (English) journals. Reviews had to be on school-aged children and/or adolescents that reported on the effects of chronic physical activity or exercise interventions, with cognitive markers, academic achievement or brain markers as outcomes. Reviews were selected independently by two authors and data were extracted using a pre-designed data extraction template. The quality of reviews was assessed using AMSTAR-2 criteria.

RESULTS

Of 908 retrieved, non-duplicated articles, 19 systematic reviews met inclusion criteria. One high-quality review reported inconsistent evidence for physical activity-related effects on cognitive- and academic performance in obese or overweight children and adolescents. Eighteen (critically) low-quality reviews presented mixed favourable and null effects, with meta-analyses showing small effect sizes (0.1-0.3) and high heterogeneity. Low-quality reviews suggested physical activity-related brain changes, but lacked an interpretation of these findings. Systematic reviews varied widely in their evidence synthesis, rarely took intervention characteristics (e.g. dose), intervention fidelity or study quality into account and suspected publication bias. Reviews consistently reported that there is a lack of high-quality studies, of studies that include brain imaging outcomes, and of studies that include adolescents or are conducted in South American and African countries.

CONCLUSIONS

Inconsistent evidence exists for chronic physical activity-related effects on cognitive-, academic-, and brain outcomes. The field needs to refocus its efforts towards improving study quality, transparency of reporting and dissemination, and is urged to differentiate between intervention characteristics for its findings to have a meaningful impact on policy.

Effects of the Enriched Sports Activities-Program on Executive Functions in Italian Children

Physical activity (PA) during childhood plays an important role in brain development. This role is played in both the structural domain, prefrontal cortex area, and in the functional domain, involving the higher cognitive functions, including the executive functions (EF). Working memory (WM), inhibition, and switching as fundamental EF were investigated in an Italian children sample before and after four months of an Enriched Sports Activities-Program (ESA-Program). EFs were assessed at pre-test and post-test using, respectively, the digit span test, the color word Stroop test, and the trail making test derived from Millisecond Software. The Italian sample was composed of 141 children aged 8.54 years. The intervention group (IG) was composed of 61 children and the control group (CG) of 80 children. Significant differences in WM (p < 0.05) were found in the IG following the ESA-Program intervention. Children's performance improved both in forward digit span (FDS1 mean difference = 0.26; p = 0.04; FDS2 mean difference = 0.21; p = 0.01) and backward digit span (BDS2 mean difference = 0.14; p = 0.02). No significant improvements were observed for inhibition and switching processes (p > 0.05). Since this finding suggests that brain functioning is sensitive to lifestyle factors, such as PA, an essential goal for ESA-Program is to emphasize the importance of PA to enhance cognitive skills in childhood and prevent sedentary life.

Physical activity, aerobic fitness, and brain white matter: Their role for executive functions in adolescence

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Aerobic fitness level, but not physical activity, is related to white matter properties in the brain.

•

The relation between physical activity and working memory is moderated by fractional anisotropy (FA) of the corpus callosum.

•

The FA of the corpus callosum and superior corona radiata moderates the relation between aerobic fitness and working memory.

Physical activity and exercise beneficially link to brain properties and cognitive functions in older adults, but the findings concerning adolescents remain tentative. During adolescence, the brain undergoes significant changes, which are especially pronounced in white matter. Studies provide contradictory evidence regarding the influence of physical activity or aerobic-exercise on executive functions in youth. Little is also known about the link between both fitness and physical activity with the brain’s white matter during puberty. We investigated the connection between aerobic fitness and physical activity with the white matter in 59 adolescents. We further determined whether white matter interacts with the connection of fitness or physical activity with core executive functions. Our results show that only the level of aerobic fitness, but not of physical activity relates to white matter. Furthermore, the white matter of the corpus callosum and the right superior corona radiata moderates the links of aerobic fitness and physical activity with working memory. Our results suggest that aerobic fitness and physical activity have an unequal contribution to the white matter properties in adolescents. We propose that the differences in white matter properties could underlie the variations in the relationship between either physical activity or aerobic fitness with working memory.

Aerobic fitness and academic achievement: A systematic review and meta-analysis

This study aims to quantify the association between aerobic fitness and academic achievement, and determine how different aerobic fitness tests and individual demographic characteristics may modify this association. It includes 41 cross-sectional and 7 longitudinal studies focusing on children and adolescents, from MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database and Web of Science. Pooled effect sizes (ES) were estimated for the association between aerobic fitness and specific domains of academic achievement. Subgroup analyses and meta-regressions were based on aerobic fitness tests and demographic characteristics. The ES for the association between aerobic fitness with language/reading-skills, mathematics-related skills and composite scores, were 0.23 (95% CI: 0.12; 0.34); 0.27 (95% CI: 0.19; 0.36) and 0.28 (95% CI: 0.12; 0.45), respectively. Subgroup analyses by aerobic fitness test modified these associations; additionally, analyses by sex or age showed differences between boys and girls as well as between children and adolescents. Finally, meta-regressions revealed a slight effect of body mass index on these associations. Cardiorespiratory fitness is positively associated with academic achievement. Associations were dependent on demographic and aerobic fitness test characteristics, being stronger in boys than in girls, and in children than in adolescents.Systematic review registration: PROSPERO CRD42017069677.

Effects of a Fundamental Motor Skill-Based Afterschool Program on Children's Physical and Cognitive Health Outcomes

Globally, more than half of school-aged children do not engage in the recommended 60 minutes of daily moderate to vigorous physical activity (MVPA). Given that developing sufficient fundamental motor skills (FMS) competence during early elementary school years is important for a child’s physical and cognitive development, the purpose of this study was to examine the effects of an 8-week FMS-based afterschool program on physical and cognitive health outcomes among elementary children. Participants were 31 K–2 students (19 girls, 12 boys; Mage = 6.65 ± 0.98) from three public elementary schools in the southwestern United States who were assigned to the intervention group (FMS-based afterschool program; n = 20) or the control group (traditional afterschool program; n = 11). A 2 × 2 repeated measures MANOVA showed significant changes in FMS competence and MVPA between the intervention and the control group over time. However, no significant changes were found in cognitive functioning. The 8-week FMS-based afterschool program showed significant improvements in FMS competence and MVPA, compared to a traditional afterschool program. This finding suggests that structured FMS-focused strategies (e.g., fun games and goal setting) can be a critical component when implementing a physical activity program to enhance children’s motor skills and physical activity behavior.

The Potential Mechanisms of Exercise-induced Cognitive Protection: A Literature Review

Dementia has become a major health concern for the aging population of the United States. Studies indicate that participation in moderate exercise, with training, has been shown to have a beneficial impact on cognition. Thus, exercise and its effects on cognitive function has become an important area of research. This review summarizes the current literature on the potential mechanisms of the benefits of exercise for cognitive function.

Associations of physical activity and screen time with white matter microstructure in children from the general population

Physical activity and sedentary behaviors have been linked to a variety of general health benefits and problems. However, few studies have examined how physical activity during childhood is related to brain development, with the majority of work to date focusing on cardio-metabolic health. This study examines the association between physical activity and screen time with white matter microstructure in the general pediatric population. In a sample of 2532 children (10.12 ± 0.58 years; 50.04% boys) from the Generation R Study, a population-based cohort in Rotterdam, the Netherlands, we assessed physical activity and screen time using parent-reported questionnaires. Magnetic resonance imaging of white matter microstructure was conducted using diffusion tensor imaging. Total physical activity was positively associated with global fractional anisotropy (β = 0.057, 95% CI = 0.016, 0.098, p = 0.007) and negatively associated with global mean diffusivity (β = -0.079, 95% CI = -0.120, -0.038, p < 0.001), two commonly derived scalar measures of white matter microstructure. Two components of total physical activity, outdoor play and sport participation, were positively associated with global fractional anisotropy (β = 0.041, 95% CI=(0.000, 0.083), p = 0.047; β = 0.053, 95% CI=(0.010, 0.096), p = 0.015, respectively) and inversely associated with global mean diffusivity (β = -0.074, 95% CI= (-0.114, -0.033), p < 0.001; β = -0.043, 95% CI=(-0.086, 0.000), p = 0.049, respectively). No associations were observed between screen time and white matter microstructure (p > 0.05). This study provides new evidence that physical activity is modestly associated with white matter microstructure in children. In contrast, complementing other recent evidence on cognition, screen time was not associated with white matter microstructure. Causal inferences from these modest associations must be interpreted cautiously in the absence of longitudinal data. However, these data still offer a promising avenue for future work to explore to what extent physical activity may promote healthy white matter development.

The Impact of Physical Activity on Brain Structure and Function in Youth: A Systematic Review

CONTEXT

Advances in neuroimaging techniques have resulted in an exponential increase in the number of studies investigating the effects of physical activity on brain structure and function. Authors of studies have linked physical activity and fitness with brain regions and networks integral to cognitive function and scholastic performance in children and adolescents but findings have not been synthesized.

OBJECTIVE

To conduct a systematic review of studies in which the impact of physical activity on brain structure and function in children and adolescents is examined.

DATA SOURCES

Six electronic databases (PubMed, PsychINFO, Scopus, Ovid Medline, SportDiscus, and Embase) were systematically searched for experimental studies published between 2002 and March 1, 2019.

STUDY SELECTION

Two reviewers independently screened studies for inclusion according to predetermined criteria.

DATA EXTRACTION

Two reviewers independently extracted data for key variables and synthesized findings qualitatively.

RESULTS

Nine studies were included (task-based functional MRI [n = 4], diffusion tensor imaging [n = 3], arterial spin labeling [n = 1], and resting-state functional MRI [n = 1]) in which results for 5 distinct and 4 similar study samples aged 8.7 ± 0.6 to 10.2 ± 1.0 years and typically of relatively low socioeconomic status were reported. Effects were reported for 12 regions, including frontal lobe (n = 3), parietal lobe (n = 3), anterior cingulate cortex (n = 2), hippocampus (n = 1), and several white matter tracts and functional networks.

LIMITATIONS

Findings need to be interpreted with caution as quantitative syntheses were not possible because of study heterogeneity.

CONCLUSIONS

There is evidence from randomized controlled trials that participation in physical activity may modify white matter integrity and activation of regions key to cognitive processes. Additional larger hypothesis-driven studies are needed to replicate findings.

Moving fast, thinking fast: The relations of physical activity levels and bouts to neuroelectric indices of inhibitory control in preadolescents

BACKGROUND

Structured vigorous physical activity (VPA) can improve cognitive control in children, but studies relating daily physical activity (PA) to cognitive control have yielded conflicting findings. While objectively measured daily PA summarizes all occurrences of PA within a registered period, a minimum duration of continuous PA is required for registration of a PA bout. Because brief bouts of high-intensity PA can account for a large proportion of children's daily activity-related energy expenditure, this study assessed whether daily and bouted VPA were selectively related to cognitive control in preadolescents relative to other PA intensities.

METHODS

A total of 75 children between the ages of 8 and 10 years (49% girls) wore an ActiGraph wGT3X+ on the hip for 7 days. The acceleration signal from the vertical axis was summarized over 1 s, 5 s, and 15 s epochs. Daily and bouted moderate PA, moderate-to-vigorous PA, and VPA were measured. PA bouts were expressed as the frequency and time spent in 2 different continuous PA bouts, one lasting ≥10 s and the other lasting ≥30 s at a given intensity. Inhibitory control was assessed using behavioral responses to a modified flanker task (mean reaction time (RT_mean) and accuracy). Attentional resource allocation and cognitive processing speed were measured using the amplitude and latency of the P3 component of event-related brain potentials, respectively. Associations between PA, behavioral indices of inhibitory control, P3 amplitude, and latency were assessed using hierarchical regression models.

RESULTS

Daily VPA was not related to RT_mean or accuracy on either congruent or incongruent trials. In contrast, more time spent in VPA bouts lasting ≥30 s predicted shorter P3 latency across epochs and flanker congruencies (all β ≤ -0.24, all p ≤ 0.04). The associations between shorter P3 latency and the time spent in moderate-to-vigorous PA bouts lasting ≥30 s were less consistent and largely limited to congruent trials (congruent: β (-0.31, -0.34)). No significant associations were observed upon correction for false discovery rate.

CONCLUSION

The pattern of uncorrected associations aligns with the dose-response literature and suggests that brief VPA bouts may yield the greatest benefits to cognitive processing speed in preadolescents. Future studies using measures of brain structure and function are needed to understand the mechanisms linking bouted VPA to neurocognitive function during childhood.

The Influence of Classroom Physical Activity Participation and Time on Task on Academic Achievement

Objectives

Determine the impact of classroom-based physically active lessons on time-on-task. Secondarily, determine the relationship of time-on-task with academic achievement controlling for key demographic variables.

Methods

Seventeen elementary schools were cluster randomized to receive classroom physical activity (A+PAAC, N=9) or control (i.e., no physical activity, N=8) for a 3-year trial. Teachers were trained to deliver physically active lessons with moderate-to-vigorous intensity targeting 100 minutes per week. Outcome measures included academic achievement (Weschler Individual Achievement Test-III), administered at baseline and repeated each spring for 3 years, time spent in moderate-to-vigorous physical activity (MVPA), and time spent on task (TOT) pre- and post-physical activity. Multilevel modeling was utilized to estimate the impacts of percent time spent in MVPA and percent TOT post-lesson on academic achievement and the change in these impacts over 3 years, accounting for dependency among observations and covariates including age, gender, race, free or reduced lunch, BMI, and fitness.

Results

A greater percentage of time performing MVPA were each significantly associated with higher math scores (p=.034) and spelling scores (p<.001), but not reading scores. Academic achievement was not associated with TOT.

Conclusion

Findings suggest that a greater percentage of time spent participating in MVPA results in higher math scores and spelling scores, but not reading scores, independent of TOT. Future studies should continue to evaluate the influence of physically active classroom lessons on time spent on task and its impact on academic achievement. Furthermore, strategies are needed to maximize impact and to determine the sustainability of physical activity's effect on classroom behavior and academic achievement.

Effects of Exercise on Cognitive Performance in Children and Adolescents with ADHD: Potential Mechanisms and Evidence-based Recommendations

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder with a complex symptomatology, and core symptoms as well as functional impairment often persist into adulthood. Recent investigations estimate the worldwide prevalence of ADHD in children and adolescents to be ~7%, which is a substantial increase compared to a decade ago. Conventional treatment most often includes pharmacotherapy with central nervous stimulants, but the number of non-responders and adverse effects call for treatment alternatives. Exercise has been suggested as a safe and low-cost adjunctive therapy for ADHD and is reported to be accompanied by positive effects on several aspects of cognitive functions in the general child population. Here we review existing evidence that exercise affects cognitive functions in children with and without ADHD and present likely neurophysiological mechanisms of action. We find well-described associations between physical activity and ADHD, as well as causal evidence in the form of small to moderate beneficial effects following acute aerobic exercise on executive functions in children with ADHD. Despite large heterogeneity, meta-analyses find small positive effects of exercise in population-based control (PBC) children, and our extracted effect sizes from long-term interventions suggest consistent positive effects in children and adolescents with ADHD. Paucity of studies probing the effect of different exercise parameters impedes finite conclusions in this regard. Large-scale clinical trials with appropriately timed exercise are needed. In summary, the existing preliminary evidence suggests that exercise can improve cognitive performance intimately linked to ADHD presentations in children with and without an ADHD diagnosis. Based on the findings from both PBC and ADHD children, we cautiously provide recommendations for parameters of exercise.

Sport Experience and Physical Activity: Event-Related Brain Potential and Task Performance Indices of Attention in Young Adults

A growing body of literature demonstrates that engaging in sport regularly and maintaining an active lifestyle have a positive impact on cognition. The purpose of this study was to examine the influence of sport experiences and physical activity on attention, and explore whether the type of sport can impact differently on the neuroelectric system using Event-Related Potentials (ERPs). Thirty-three young adults (mean age = 19.72 ± 1.25) were divided according to their sport experience into swimmers, karateka, and irregular exercisers. Participants performed auditory oddball tasks, while measures of task performance and ERPs were collected. The results indicated that exercisers, regardless of their sport experience, exhibited a larger and shorter P3 compared to irregular exercisers. However, no significant difference was observed in the reaction time (RT) between groups. No statistically significant differences in the RT and P3 were present between swimmers and karateka. These findings suggest that sport experiences, regardless of the type, are associated with a larger amount of neural attentional resources and faster stimulus evaluation speed. The results replicate previous studies that have reported improved cognitive functions in more active individuals. They further extended the current knowledge by indicating that both swimming and karate influence attention and do not differentially alter the brain response.

Cardiorespiratory fitness as a mediator of the relationship between birth weight and cognition in school children

Objectives: To examine differences in cognition parameters by birth weight categories and to analyze whether the relationships between birth weight and cognitive functions are mediated by cardiorespiratory fitness (CRF) in schoolchildren. Methods: A cross-sectional study using a sample of 664 school children from the MOVI-Kids study. Variables: i) cognitive function measured by the Battery of General and Differential Aptitudes (BADyG); ii) birth weight, reported by parents; and iii) CRF (20-m shuttle run test). ANCOVA models were estimated to assess differences in cognitive function categories across birth weight and CRF categories. Mediation analysis was conducted with Hayes' PROCESS macro. Results: CRF is a full mediator of the association between birth weight with the verbal and numerical factors, and general intelligence; and is a partial mediator when logical reasoning and the spatial factor were the dependent variables. The available data suggest that, in schoolchildren, the influence of birth weight on cognitive function is mediated by CRF. Conclusions: These findings highlight that children with lower birth weight values and lower fitness levels should be target subgroups to improve children's cognition, in which long-life physical activity interventions at early ages are a priority.