Relation between physical fitness and executive function variables in a preschool sample

Associations between cardiorespiratory fitness and executive function in Chinese adolescents

Executive function (EF) has a significant impact on career achievement in adolescence and later adulthood, and there are many factors that influence EF. Cardiorespiratory fitness (CRF) is an important factor in the physical fitness of adolescents and is of great significance to healthy development. However, the current association between CRF and EF in Chinese adolescents is still unclear. For this reason, this study analysed the association between CRF and EF. A three-stage stratified cluster sampling method was used to investigate the demographic information, CRF, EF and multiple covariates of 1245 adolescents in China. One-way analysis of variance and chi-square test were used to compare the EF status of different CRFs. The association between CRF and EF was analysed using multiple linear regression analysis and logistic regression analysis. Multiple linear regression analysis showed that, after adjusting for relevant confounding factors, compared with Chinese adolescents with VO2max < P25, the inhibition function reaction time, 1back reaction time, 2back reaction time, and cognitive flexibility response time of adolescents with VO2max > P75 decreased by 1.41 ms, 238.73 ms, 273.09 ms, 74.14 ms. Logistic regression analysis showed that compared with Chinese adolescents with VO2max > P75, Chinese adolescents with VO2max < P25 developed inhibitory function dysfunction (OR 2.03, 95% CI: 1.29, 3.20), 1back dysfunction (OR 6.26, 95% CI 3.94, 9.97), 2back dysfunction (OR 8.94, 95% CI 5.40, 14.82), cognitive flexibility dysfunction (OR 2.26, 95% CI 1.44, 3.57) The risk was higher (P < 0.01). There is a positive association between CRF and EF in Chinese adolescents. High-grade CRF adolescents have higher EF levels, that is, shorter response times. This study provides reference and lessons for better promoting adolescents' executive function development in the future.

Actigraphy-assessed sleep duration and quality and executive function in a sample of typically developing preschoolers

Sleep is essential for cognitive development and brain maturation during early childhood. Studies focused on preschool populations using objective measures of sleep are still scarce. The objective of this study was to examine the associations between objective measures of sleep duration and quality with executive functioning in a 133 non-clinical sample of Spanish participants (Mage = 60.33 months, SD = 9.04; ages 41-77 months; 51.1% girls). Sleep was assessed for five weeknights using actigraphy; Shape School task was applied to assess inhibition and cognitive flexibility; and Word Span task was used to assess working memory. The results revealed that relation between sleep and executive functioning was significant for inhibition and working memory. Preschoolers with higher sleep efficiency showed better results in executive functioning tasks after controlling for the effect of age. Additionally, age and sleep duration and quality variables were predictive of inhibition, working memory, and cognitive flexibility. These results suggest that the different dimensions of sleep could play an important role in the development of executive functions during preschool age. Therefore, improving sleep could lead to an improvement in children's executive functioning in both clinical and educational contexts.

A study on the correlation between physical fitness index and executive function in Chinese adolescents

OBJECTIVE

To explore the relationship between physical fitness index and executive function in Chinese adolescents, and to provide a reference for improving the development of executive function in Chinese adolescents.

METHODS

From September to December 2023, 5336 adolescents aged 13 to 18 years were selected by stratified whole cluster random sampling method in six regions of China for physical fitness and executive function tests. The relationship between adolescent physical fitness index and executive function was analyzed using t-test, ANOVA, Pearson's correlation, and logistic regression.

RESULTS

The correlation coefficients between adolescents' physical fitness index and inhibitory control reaction time were all 0.00094, p > 0.05; the correlation coefficients between adolescents' physical fitness index and working memory (1-back, 2-back) reaction time were -0.13 and -0.093, respectively, p < .05; the correlation coefficients between adolescents' physical fitness index and cognitive flexibility reaction time were -0.17 and -0.18, p < .05. Logistic regression analyses showed that 1-back, 2-back, and cognitive flexibility were significantly and positively correlated with physical fitness index in Models 1, 2, and 3 (all p values less than.01). The coefficients of inhibitory control were not significant in all three models (p > .05), and there was no significant relationship with physical fitness index.

CONCLUSION

The physical fitness index of Chinese adolescents has a significant positive correlation with working memory and cognitive flexibility, but not with inhibitory control, i.e. the higher the physical fitness index, the better the working memory and cognitive flexibility.

Optimal exercise intensity for improving executive function in patients with attention deficit hyperactivity disorder: systematic review and network meta-analysis

This study aimed to compare and rank the effectiveness of optimal exercise intensity in improving executive function in patients with ADHD (Attention deficit hyperactivity disorder, ADHD) through a comprehensive comparison of direct and indirect evidence. A systematic search was performed in five electronic databases to explore the optimal exercise intensity for improving executive function in patients with ADHD by directly and indirectly comparing a variety of exercise intervention intensities. In addition, the isolated effects of exercise on improving executive function in patients with ADHD were explored through classical meta-analysis of paired direct comparisons. Twenty-nine studies were retrieved and included in this study. Classical paired meta-analysis showed that for the patients with ADHD in the age group of 7-17 years, statistical difference was observed for all the parameters of exercise interventions (intensity, frequency, period, and training method), the three dimensions of executive function, the use of medication or not, the high and low quality of the methodological approach. Network meta-analysis showed that high-intensity exercise training was optimal for improving working memory (97.4%) and inhibitory function (85.7%) in patients with ADHD. Meanwhile, moderate-intensity exercise training was optimal for improving cognitive flexibility (77.3%) in patients with ADHD. Moderate to high intensity exercise training shows potential for improving executive function in these patients. Therefore, we recommend applying high-intensity exercise intervention to improve executive function in patients with ADHD to achieve substantial improvement.

Recreational gymnastics exercise of moderate intensity enhances executive function in Chinese preschoolers: A randomized controlled trial

The current study aimed to investigate the impact of recreational gymnastics on executive function in Chinese preschoolers, with a focus on gymnastics potential to enhance core components of executive function. A total of 63 preschool children who received full-time education were randomly assigned to either an intervention group (N = 31, mean age = 66.27 months, SD = 3.12 months) or a control group (N = 32, mean age = 66.79 months, SD = 3.34 months). The intervention group engaged in recreational gymnastics for 60 min, three times a week for 12 weeks. Meanwhile, the control group continued with their typical outdoor activities at kindergarten and did not participate in any organized sports. The intervention program was primarily conducted through group play and was facilitated by teachers who underwent standardized training. Various simple and complex tasks were utilized to evaluate delay gratification (Snack delay and Wrapped gift), inhibitory control (Stop signal task and Circle drawing task), working memory (Letter memory task and Keep track task), and cognitive flexibility (Go/No-Go task and Dots task). The analysis of covariance revealed that the children who participated in the intervention outperformed the control group on most simple and complex executive function tasks. Specifically, these children demonstrated an enhanced ability to regulate persistent responses, process and update information, and manage high cognitive conflict. The findings of this investigation lend support to the hypothesis that moderate-intensity recreational gymnastics is an efficacious means of enhancing executive function in early childhood. Future research should employ a larger sample size, incorporate a long-term follow-up design, and utilize a multi-method approach to further substantiate the impact of moderate-intensity gymnastics on the executive function of young children, as well as to investigate its underlying mechanism and generalizability.

Relationship between cardiorespiratory fitness and executive function of Chinese Tibetan adolescents aged 13-18

OBJECTIVES

Explore the correlation between cardiorespiratory fitness (CRF) and execution function (EF) of Chinese Tibetan adolescents at high altitude (HA) areas.

DESIGN

A cross-sectional survey was used to study 1138 participants aged 13-18 (47.72% boys) at baseline.

METHODS

Lhasa (3650 m), Nagqu (4500 m), Qamdo (3500 m), and Nyingchi (3100 m) in China were chosen. CRF was measured by the 20 m shuttle run test (20mSRT) and a subsequent estimation of their maximal oxygen consumption (V̇O2max) was calculated using the Léger equations. The three core EFs (inhibition, working memory, and cognitive flexibility) were tested by a modified Eriksen flanker, N-back, and a more-odd shifting. The association between CRF and EF was explored by Pearson correlation, one-way ANOVA, and stratified regression.

RESULTS

The reaction time (RT) of 1-back, cognitive flexibility with V̇O2max showed a declining trend, (F = 34.475, 27.498, P < 0.01). Interestingly, 2-back RT went up and then went down with V̇O2max. (F = 29.55, P < 0.01). After increasing V̇O2max as a variable, a stratified regression analysis with the RT for 1-back, 2-back, and cognitive flexibility showed that ΔR2 equaled 0.107 ms, 0.071 ms, and 0.091 ms, respectively (P < 0.01). With V̇O2max increased by 1 mL/kg/min, the RT of 1-back, 2-back, and cognitive flexibility shortened 14.697 ms, 15.689 ms, and 11.771 ms, respectively.

CONCLUSIONS

CRF was positively associated with working memory, and cognitive flexibility development among Chinese Tibetan adolescents living at HA areas, respectively.

Association of physical activity and fitness with executive function among preschoolers

It is well-documented in the literature that high levels of regular physical activity (PA), low levels of sedentary behavior (SB), and high levels of cardiorespiratory fitness (CRF) are associated with superior cognitive functioning, especially with regard to older populations. However, concerning other age groups (e.g., preschoolers) the available evidence documenting such a positive relationship is relatively scarce. Thus, this study aimed to investigate the association of time spent in different PA intensity zones and CRF with executive functions (EFs) in preschool-age children. To this end, preschoolers (n = 127) aged 3 to 6 years were recruited from 9 kindergarten classes in 2 districts of Shenzhen, China. The amount and the intensity of PA were assessed via accelerometry, and the CRF level was quantified by the 20-meter shuttle run test. EFs including inhibitory control and working memory were assessed using the one-on-one iPad-based Early Year Toolbox. Results suggested that children who had a higher CRF level ("impulse control" scores: β = 0.34, p < .001; "Go" accuracy: β = 0.31, p < .001; "No-Go" accuracy: β =0.28, < .001) and spentmore time in moderate-to-vigorous physical activity (MVPA) ("impulse control" scores: β = 0.50, p < .001; No-Go" accuracy: β = 0.52, p < .001) had higher scores on inhibitory control tasks, and those who had a higher CRF level had higher scores on a working memory task (β = 0.24, p < .05). The findings are discussed in light of the positive roles of MVPA and CRF for promoting EFs, but also consider the disproportionate association of PA and CRF with working memory relative to inhibition.

Biological, behavioral, and social correlates of executive function in low-income preschoolers: Insights from the perspective of the networks

Behavioral, biological, and social correlates may be related to the association between executive function (EF) and physical activity (PA), when considering such variables as an integrated and non-linear system. Thus, the aim of the present study was to investigate the relationships between EF, PA and associated correlates in low-income preschoolers according to a network perspective. Thus, 142 preschoolers of both sexes, age 3-to-5-years-old (51% girls) were analyzed. Light, moderate and vigorous PA, cardiorespiratory fitness (CRF), body mass index, family income, preterm birth, presence of siblings, presence of other children at home and the child's primary caregiver were assessed. Our results showed that EF was positively associated with age (b = 0.47), child's primary caregivers (b = 0.37), moderate PA (b = 0.30) and CRF (b = 0.25). Negative associations were seen with preterm birth (b = -0.50), vigorous PA (b = -0.34), presence of other children at home (b = -0.25), and sex (b = -0.33). The network's centrality indicators highlighted preterm birth and moderate PA as the most important variables in the network. Future interventions aiming to increase low-income preschoolers' EF should focus on increasing moderate PA, with special attention to preterm children.

Students from a Public School in the South of Chile with Better Physical Fitness Markers Have Higher Performance in Executive Functions Tests-Cross-Sectional Study

In the past few years, the level of physical fitness in children has decreased globally. According to the SIMCE test carried out in 2015, 45% of 8th year students in Chile were overweight. Moreover, international studies have shown that being overweight is associated with the development of chronic illnesses, negatively affecting cognitive mechanisms and processes. Nevertheless, there is little to no evidence that analyzes the relationship between physical fitness and executive functions in students, at a national level. The aim was to analyze the relationship between cardiorespiratory, musculoskeletal, and motor fitness, and performance in an executive functions test, in students from a public school in the south of Chile. A qualitative, descriptive -correlational, non-experimental, and cross-sectional approach was used. In total, 100 students between 9 and 12 and 11 months of age from a public school in the south of Chile completed the physical fitness assessments through the ALPHA fitness test, and 81 students completed the executive function assessments through the ENFEN test. It was evidenced that students who achieved a longer duration of time and a later stage in the Course Navette test, more centimeters in the standing broad jump (SBJ) test, and a shorter duration in the 4 × 10 shuttle run obtained a better score in the gray trail test. Additionally, students who presented a stronger dominant handgrip scored higher in the colored trail tests. We conclude that students who show a higher level of physical fitness also present a better development of executive functions such as working memory and inhibitory control. In addition, these results suggest physical condition is a factor to consider for better cognitive and school performance.

Effects of acute exercise with different modalities on working memory in men with high and low aerobic fitness

OBJECTIVES

This study aimed to determine the effects of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) on working memory in individuals with high and low aerobic fitness.

DESIGN

The protocol adopted a between-subjects crossover design.

METHODS

Forty healthy male college students (mean age = 19.59 ± 1.00 years) were assigned to high fitness (n = 20) or low fitness (n = 20) groups based on their estimated maximum oxygen consumption (VO_2max) in the 20 m shuttle run test. All participants were instructed to engage in three acute exercise interventions (10 min HIIE, 20 min HIIE, 20 min MICE) and a reading control intervention on separate days in a randomized order. A spatial 2-back task was performed before and after each intervention to assess working memory.

RESULTS

Analyses of the 2-back task performance revealed that the working memory of high and low fitness participants benefited from different modalities of acute exercise. Specifically, reaction time in the 2-back task was significantly shorter after 20 min HIIE compared to pre-exercise in high fitness participants, whereas low fitness participants had significantly faster reaction time in the 2-back task after 20 min MICE and 10 min HIIE relative to pre-exercise.

CONCLUSIONS

The effects of acute aerobic exercise on working memory are modulated by a combination of exercise modality and aerobic fitness. This finding has important implications for providing experimental evidence that participants choose appropriate exercise to undertake based on their level of aerobic fitness to improve cognitive performance.

Spatial statistical machine learning models to assess the relationship between development vulnerabilities and educational factors in children in Queensland, Australia

BACKGROUND

The health and development of children during their first year of full time school is known to impact their social, emotional, and academic capabilities throughout and beyond early education. Physical health, motor development, social and emotional well-being, learning styles, language and communication, cognitive skills, and general knowledge are all considered to be important aspects of a child's health and development. It is important for many organisations and governmental agencies to continually improve their understanding of the factors which determine or influence development vulnerabilities among children. This article studies the relationships between development vulnerabilities and educational factors among children in Queensland, Australia.

METHODS

Spatial statistical machine learning models are reviewed and compared in the context of a study of geographic variation in the association between development vulnerabilities and attendance at preschool among children in Queensland, Australia. A new spatial random forest (SRF) model is suggested that can explain more of the spatial variation in data than other approaches.

RESULTS

In the case study, spatial models were shown to provide a better fit compared to models that ignored the spatial variation in the data. The SRF model was shown to be the only model which can explain all of the spatial variation in each of the development vulnerabilities considered in the case study. The spatial analysis revealed that the attendance at preschool factor has a strong influence on the physical health domain vulnerability and emotional maturity vulnerability among children in their first year of school.

CONCLUSION

This study confirmed that it is important to take into account the spatial nature of data when fitting statistical machine learning models. A new spatial random forest model was introduced and was shown to explain more of the spatial variation and provide a better model fit in the case study of development vulnerabilities among children in Queensland. At small-area population level, increased attendance at preschool was strongly associated with reduced physical and emotional development vulnerabilities among children in their first year of school.

Aerobic fitness and fine motor skills are related to switching and updating in typically developing children

Movement is essential for everyday life and closely related to cognitive skills. The aim of the current research was to investigate whether different aspects of physical activity, i.e., aerobic fitness and motor skills, contribute above and beyond each other to the variance in children's executive functioning. Children aged 8-13 years (N = 129, 58 females, M_age = 10.7 years, SD_age = 1.6 years) participated in the current cross-sectional study. Aerobic fitness was assessed by the Progressive Aerobic Cardiovascular Endurance Run (PACER). Motor skills were assessed using the standardized Movement Assessment Battery for Children 2nd edition (M-ABC-2), including fine motor skills, balance skills, and object control. Components of executive functions (inhibition, switching, updating) were assessed using the following tasks: an animal Stroop task, a local-global task, and a 2n-back task. Hierarchical regressions were conducted to analyze the relative importance of aerobic fitness and motor skills for children's executive functions. Results indicated that aerobic fitness and fine motor skills were significantly related to switching and updating, whereas relations to inhibition were non-significant. Furthermore, it was found that fine motor skills explained additional variance above aerobic fitness in switching and updating whereas aerobic fitness did not add additional variance above fine motor skills in switching and updating. Balance and object control skills were not related to the three core executive functions. Results support the notion that aerobic fitness and fine motor skills are differently related to executive functions and highlight the importance of considering multiple components of constructs in future research.

The relationship of muscular endurance and coordination and dexterity with behavioral and neuroelectric indices of attention in preschool children

This study investigated the associations of non-aerobic fitness (NAF) and motor competence (MC) with attention in 4–6 year-old preschoolers. The allocation of attentional resources and speed of stimulus categorization were examined using the amplitude and latency of P3 of event-related potentials respectively, while cortical activation related to general attention and task-specific discriminative processes were examined using event-related desynchronization (ERD) at lower (8–10 Hz) and upper (10–12 Hz) alpha frequencies, respectively. Seventy-six preschoolers completed NAF (muscular power, muscular endurance, flexibility, balance) and MC (coordination and dexterity, ball skills, agility and balance) test batteries. Electroencephalogram was recorded while participants performed an auditory oddball task. After controlling for age and MC, muscular endurance was positively related to P3 amplitude. MC and its coordination and dexterity sub-component were positively related to task performance, with higher levels of coordination and dexterity showing an additional association with greater upper alpha ERD between 700 and 1000 ms following stimulus onset after controlling for age and NAF. These findings suggest relationships of NAF and MC with early childhood neurocognitive function. Specifically, muscular endurance is related to the neuroinhibition in facilitating effective allocation of attentional resources to stimulus evaluation while coordination and dexterity are related to cortical activation underlying strategic attentional preparation for subsequent stimulus evaluation.

Validity and Reliability of the International FItness Scale (IFIS) in preschool children

OBJECTIVES

Examine the validity and reliability of parent-reported International FItness Scale (IFIS) in preschool-age children.

METHOD

A cross-sectional study of 3051 Spanish preschoolers (3-5 years). Fitness was measured by PREFIT fitness test battery and reported by parents using an adapted version of the IFIS. Waist circumference was evaluated, and the waist-to-height ratio (WHtR) was calculated. Seventy-six parents of randomly selected schoolchildren completed the IFIS twice (two weeks apart) for a reliability assessment.

RESULTS

ANCOVA, adjusted for sex, age and WHtR, showed that preschoolers who were scored by their parents as having average-to-very good fitness had better levels of measured physical fitness than those preschoolers who were classified as having "very poor/poor" fitness levels (18.1laps to 22.1laps vs 15.6laps for cardiorespiratory fitness; 6.6 kg to 7.5 kg vs 5.3 kg for muscular fitness-handgrip-; 71.7 cm to 76.4 cm vs 62.0 cm for muscular fitness-standing long jump-; 17.2s to 16.2s vs 18.2s for speed/agility; and 11.2s to 15.6s vs 8.7s for balance; p < 0.001). The weighted kappa for concordance between parent-reported fitness levels and objective assessment was poor (κ ≤0.18 for all fitness measures). Overall, the mean values of the abdominal adiposity indicators were significantly lower in high-level fitness categories reported by parents than in low-level fitness categories (p < 0.05). The test-retest reliability of IFIS items ranged from 0.46 to 0.62.

CONCLUSIONS

The reliability of the parent-reported IFIS are acceptable, but the concordance between parents reported and objectively measures fitness levels is poor, suggesting that parents' responses may not be able to correctly classify preschoolers according to their fitness level.

The association between the health-related physical fitness and inhibitory control in preschool children

Background

Inhibitory control develops rapidly during the preschool stage, and development of inhibitory control in this period is significant for the healthy growth of the future. However, most studies paid more attention to children and adolescents in recent years, but less focus on preschool children. Therefore, the purpose of this study was to explore the association between the health-related physical fitness and inhibitory control in preschool children.

Methods

This cross-sectional study was based on a baseline data from randomized controlled trial by cluster sampling(including 128 preschoolers, 70 boys, 58girls).The health-related physical fitness T-score (HPFT) was obtained by adding standard scores of six indicators: body mass index, handgrip strength, standing long jump, one-leg balance, 2 × 10 m shuttle run test, and 20 m shuttle run test. Inhibitory control was assessed using the flanker task and reflected by reaction time and accuracy.

Results

A total of 120 preschoolers were included in the final statistical analysis. After adjusting the confounders, HPFT was associated with reaction time (β=-2.49 ms, 95%CI: -4.22, -0.75). Similarly, a negative association was observed between one-leg balance and reaction time (β=-12.04 ms, 95%CI: -18.94, -5.15), and between 20 m shuttle run test and reaction time (β=-23.28 ms, 95%CI: -37.00, -9.56). Compared with the participants in the lowest tertile, HPFT (β=-158.74, 95%CI: -309.63, -7.84), one-leg balance (β=-267.25 ms, 95%CI: -420.71, -113.79) and 20 m shuttle run test (β=-215.58 ms, 95%CI: -374.67, -56.49) were all negatively associated with reaction time of those in the highest tertile.

Conclusions

Negative relationships between HPFT and RT of the inhibitory control were observed in preschoolers. To have better inhibitory control, it’s suggested that HPFT of preschoolers should be at least 249. These findings are of great significance for the early improvement of HPFT and the development of inhibitory control in preschool children.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03163-y.

Field-based physical fitness assessment in preschool children: A scoping review

Physical fitness, which can be measured using various health- and skill-related components, is an important indicator of child development and health status. This study undertakes a scoping review on physical fitness assessment methods in preschool children to summarize the most widely used field-based physical fitness batteries and specific test items for preschool children. A search of the literature in English was undertaken using two major electronics databases, which yielded 76 literatures that met the inclusion and exclusion criteria. These literatures took the quantitative indicators of physical fitness as the outcome variables in 3-6-year-old children. This review found that of these 76 literatures analyzed, 71.1% came from Europe and 89.5% were published after 2010. The results showed six physical fitness test batteries, with the assessing FITness in PREschoolers (PREFIT) battery is the most widely used, and specific test items such as body mass index (BMI), standing long jump, handgrip, one-leg stance, sit and reach, 20 m shuttle run test (SRT)-PREFIT, and 4 × 10 m SRT are widely used in corresponding components. Therefore, we recommend that an international standard for some specific test items should be developed for preschool children to facilitate more widespread adoption and promote physical fitness assessment for preschool children.

Physical Activity, Fitness, School Readiness, and Cognition in Early Childhood: A Systematic Review

BACKGROUND

Early childhood is an important age for brain and cognitive development. Given the support of physical activity and fitness on cognition and academic performance in older children, more research has emerged recently focusing on younger children. In this systematic review, the authors review the relations between physical activity/fitness and academic-related (ie, school readiness and cognitive) outcomes in early childhood.

METHODS

A search was conducted from PubMed, PsycINFO, Web of Science, ERIC databases, and reference lists for articles that had participants aged less than 6 years were written in English, and were in peer-reviewed journals. Articles were excluded if the design was a case study or case series report. The Grading Recommendations Assessment, Development and Evaluation framework was followed to assess the quality of evidence by study design.

RESULTS

Sixty-eight articles reporting on 72 studies (29 observational and 43 experimental) were included. The majority of study effects were mixed, and the quality of evidence varied from very low to low.

CONCLUSIONS

A clear consensus about the role of physical activity and fitness on academic-related outcomes in early childhood is still lacking given the high heterogeneity in methodological approaches and overall effects. Additional high-quality studies are needed to determine what specific dosages of physical activity are impactful at this age.

Interrelations of Physical Fitness and Cognitive Functions in German Schoolchildren

This study investigated the relationship between different levels of physical fitness and cognitive functions in boys and girls. Schoolchildren from a comprehensive school in Germany (n = 211, 39% girls, 5th and 6th grade) attended regular or sport-focused classes with different numbers of physical education (PE) classes per week (3 vs. 5-6 h). Performance of physical fitness was tested according to endurance, strength, speed, coordination and flexibility. Four computerized instruments (switch task, 2-back task, Corsi block-tapping task and flanker task) were used to test cognitive functions. Additional predictors, sex, age, PE class, Body Mass Index and physical activity, were included in analyses. The results showed that physical fitness was associated with improved attention and memory functions in children, although the associations were mostly small. After Bonferroni correction, mainly coordination was related to improved cognition. Physical activity, i.e., step counts, PE class and sex were associated with specific cognitive outcomes. These findings may be important for effective health promotion, and supporting children's education in the school environment. Sex-specific physical activities in school could potentially lead to greater cognitive benefits in children. Randomized trials are needed to replicate these results.

How are academic achievement and inhibitory control associated with physical fitness, soil-transmitted helminth infections, food insecurity and stunting among South African primary schoolchildren?

BACKGROUND

Cardiovascular fitness has been associated with both executive function and academic achievement in multiple cohort studies including children and adolescents. However, research is scarce among children from low- and middle-income countries. Hence, this paper focuses on South African primary schoolchildren living in marginalized areas and examines if academic achievement and inhibitory control can be explained by children's age, socioeconomic status, soil-transmitted helminth infections, food insecurity, stunting, grip strength, and cardiorespiratory fitness.

METHODS

The sample of this cross-sectional study consisted of 1277 children (48% girls, mean age: 8.3 years). Data were assessed via questionnaires, stool samples, anthropometric measurements, 20 m shuttle run test, grip strength test, Flanker task, and school grades. Data were analysed with mixed linear regression models with random intercepts for school classes, separately for boys and girls.

RESULTS

Higher socioeconomic status was most closely associated with academic achievement among boys (p < 0.05), whereas higher levels of cardiorespiratory fitness and not being stunted explained most variance in academic achievement in girls (p < 0.05). Higher age turned out to be associated with better performance in the Flanker task (p < 0.01). Additionally, in boys, higher grip strength was associated with better information processing and inhibitory control of attention (p < 0.01), whereas in girls, higher cardiorespiratory fitness levels were positively associated with these cognitive abilities (p < 0.05).

CONCLUSIONS

Academic performance has been shown to be compromised in schoolchildren living in marginalised areas, compared to schoolchildren in less disadvantaged parts of South Africa. The present study suggests that cardiorespiratory fitness and grip strength are two potentially modifiable factors that are associated with children's academic achievement and cognitive performance, and that should be targeted in future school-based interventions.

24-hour movement behaviour and executive function in preschoolers: A compositional and isotemporal reallocation analysis

Adherence to healthy behaviours promotes several health benefits in preschool children, including executive function (EF). Recently, the predictive power of the 24-hour movement behaviour (24 h MB) composition on health outcomes has been evidenced; however, its relationship with EF in preschoolers is unknown. Thus, the present study had two objectives: (1) to analyse the associations between the 24 h MB composition and EF of preschoolers; and (2) to investigate the theoretical changes in EF when time in different movement behaviours is reallocated. This cross-sectional study was carried out with 123 preschoolers (3-5 years old) of low socioeconomic status. Physical activity (PA) and sedentary behaviour were assessed using an accelerometer for 7 days, sleep time was obtained through interviews with parents, and EF was measured using the Early Tool Box battery. To verify the association between 24 h MB and EF, compositional data analysis was used, and for time reallocation, compositional isotemporal substitution analysis was utilized. It was observed that the 24 h MB composition was positively associated with EF (p < .0001; R² = 0.34), and that reallocating 5, 10, 15 or 20 min of the time spent on sleep and light PA to moderate-to-vigorous PA, respectively, was associated with significant improvements in EF (p < .05). These findings provide hitherto unseen insight into the relationship between 24 h MB and EF in preschool children, and warrants consideration for researchers and practitioners seeking to improve EF and PA in preschool children.