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Neurotrophic factors and cardiorespiratory fitness are both considered important in developmental trajectories but their link to brain health remains poorly understood. The aims of the study were to examine whether levels of plasma-derived neurotrophic factors were associated with brain health indicators in children with overweight or obesity; and to test whether these associations were moderated by cardiorespiratory fitness. 100 children (41% girls) were included in this analysis. Plasma levels of brain-derived neurotrophic factor, insulin-like growth factor-1, vascular endothelial growth factor A, and epidermal growth factor were determined by XMap technology. Academic performance and executive function were assessed using validated neuropsychological tests. Hippocampal volume was measured using magnetic resonance imaging. Cardiorespiratory fitness was assessed using the 20-m Shuttle Run Test. Insulin-like growth factor-1 was positively associated with cognitive flexibility. Stratified analyses by fitness categories (i.e. unfit vs. fit) showed that brain-derived neurotrophic factor was positively associated with right posterior hippocampal volume in fit children, and epidermal growth factor was negatively associated with right hippocampal, and right anterior hippocampal volumes in their unfit peers, with a moderating role of cardiorespiratory fitness in these associations. However, all these significant associations disappeared after correction for multiple comparisons. The association between neurotrophic factors and brain health indicators in children with overweight/obesity was neither strong nor consistent. These results could help enhance our understanding of determinants of brain health in children with overweight/obesity. Highlights This study provides novel findings on the associations between neurotrophic factors and a wide range of brain health indicators in children. This study additionally explored the role of cardiorespiratory fitness in these associations. The association between neurotrophic factors and brain health in children with overweight/obesity was neither strong nor consistent. Cardiorespiratory fitness moderated the associations of brain-derived neurotrophic factor and epidermal growth factor with right hippocampal volume.

Walking cadence (steps/min) has emerged as a valid proxy of physical activity intensity, with consensus across numerous laboratory-based treadmill studies that ≥100 steps/min approximates absolutely defined moderate intensity (≥3 metabolic equivalents; METs). We recently reported that this cadence threshold had a classification accuracy of 73.3% for identifying moderate intensity during preferred pace overground walking in young adults. The purpose of this study was to evaluate and compare the performance of a cadence threshold of ≥100 steps/min for correctly classifying moderate intensity during overground walking in middle- and older-aged adults.Participants (N = 174, 48.3% female, 41-85 years of age) completed laboratory-based cross-sectional study involving an indoor 5-min overground walking trial at their preferred pace. Steps were manually counted and converted to cadence (total steps/5 min). Intensity was measured using indirect calorimetry and expressed as METs. Classification accuracy (sensitivity, specificity, accuracy) of a cadence threshold of ≥100 steps/min to identify individuals walking at ≥3 METs was calculated.The ≥100 steps/min threshold demonstrated accuracy of 74.7% for classifying moderate intensity. When comparing middle- vs. older-aged adults, similar accuracy (73.4% vs. 75.8%, respectively) and specificity (33.3% vs. 34.5%) were observed. Sensitivity was high, but was lower for middle- vs. older-aged adults (85.2% vs. 93.9%, respectively).A cadence threshold of ≥100 steps/min accurately identified moderate-intensity overground walking. Furthermore, accuracy was similar when comparing middle- and older-aged adults. These findings extend our previous analysis in younger adults and confirm the appropriateness of applying this cadence threshold across the adult lifespan.

Purpose: To examine the effects of a 14-week gamification-based physical education teaching program on fitness in college students. Method: A convenience sample of 112 college students (21.22 ± 2.55 years) was distributed among a gamification-based group or a control group (i.e., traditional teaching). College students from the gamification group used a game-based mobile app under the narrative of “STAR WARS™” with a countdown, so they had to gain lifetime. Cardiorespiratory fitness was assessed by the 20-m shuttle run test. Muscular fitness was measured by the handgrip strength and the standing broad jump tests. Results: Participants from the gamification program reported a significantly higher cardiorespiratory fitness and upper and lower body muscular fitness at postintervention, indicated by an effect size of 0.86 (p p = .018), and 0.52 (p Conclusion: Gamification can have an important implication on students’ motivation toward higher fitness.

We investigated the association of anthropometric neonatal data (birth length and birth weight) and breastfeeding practices (exclusive and any breastfeeding) with hippocampal functional connectivity and its academic implication in children with overweight/obesity.Ninety six children with overweight/obesity aged 8-11 years (10.01 ± 1.14), from the ActiveBrains project were included in this cross-sectional study. Anthropometric neonatal data were collected from birth records, whereas breastfeeding practices were reported by parents. A 3.0 Tesla Siemens Magnetom Tim Trio system was used to acquire T1-weighted and resting-state functional magnetic resonance images. Academic performance was assessed by the Woodcock-Muñoz standardized test. Hippocampal seed-based methods with post-hoc regression analyses were performed. Analyses were considered significant when surpassing Family-Wise Error corrections.Birth weight showed a positive association with the connectivity between the hippocampus and the pre- and postcentral gyri, and the cerebellum. In addition, breastfeeding was negatively associated with the connectivity between the hippocampus and the primary motor cortex and the angular gyrus. Any breastfeeding, in turn, showed a positive association with the connectivity between the hippocampus and the middle temporal gyrus. None of the connectivity outcomes related to early life factors was coupled with better academic abilities (all p 0.05).Our findings suggest that birth weight at birth and breastfeeding are associated with hippocampal connectivity in children with overweight/obesity. Despite this, how the results relate to academic performance remains a matter of speculation. Our findings suggest that clinicians should recognize the importance early life factors for potentially avoiding consequences on offspring's brain development.

ObjectivesTo examine 1) the chronic effects of a 20-week physical exercise program on device-assessed sleep and on sleep-disordered breathing (SDB); and 2) whether attending to a session of the exercise program had effects on device-assessed sleep the subsequent night in children with overweight/obesity.MethodsA total of 99 children with overweight/obesity (n=47 in the exercise group) participated in this secondary analysis of the ActiveBrains randomized clinical trial. The exercise program included a combination of aerobic and resistance exercise training, 3-5 days/week (90 min/session). The control group was asked to maintain usual lifestyle. Sleep outcomes were measured using wrist actigraphy and included: total sleep time, total time in bed, sleep efficiency, and wake after sleep onset (WASO) time. SDB was assessed via the Paediatric Sleep Questionnaire.ResultsThe ActiveBrains exercise program had a statistically significant effect on WASO time (−10.8 min/day, -0.5 standard deviations (SD), P=0.040). Furthermore, we observed a small non-statistically significant effect on sleep efficiency (+2%, 0.4 SD, P=0.1). No other chronic effects were observed on the other sleep outcomes. The nights (at maximum of 4) after attending the ActiveBrains exercise sessions, children showed higher total sleep time (+8 min, P=0.17), sleep efficiency (+1%, P=0.15), and lower WASO time (−6 min, P=0.18) although did not reach statistical significance.ConclusionA 20-week physical exercise program reduced WASO time in children with overweight/obesity in comparison with control group peers, yet we did not observe effects on SDB. Future randomized trials that include a clinical sample of children with poor sleep health at baseline are needed to better appreciate the role of exercise in sleep health.Clinal Trial RegistrationThe ActiveBrains project is registered at ClinicalTrials.gov, no. NCT02295072. Data Sharing Statement: We did not obtain children’s parents consent to widely share the data nor was it included in the IRB protocol.What’s known on this subjectSleep is an essential component in children’s health. Previous researchers have found positive effects of exercise on sleep in adolescents with obesity, but the literature in childhood obesity is lacking.What this study addsA physical exercise program showed positive effects on device-assessed sleep habits in children with overweight/obesity, yet not on sleep-disordered breathing. Exercise programs should be promoted in children to improve their sleep health, especially in those with overweight/obesity.

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, andworking memory), and academic performancewere 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 improvementswere not identified., Spanish Government DEP2013-47540 DEP2016-79512-R DEP2017-91544-EXP, European Commission European Commission European Commission Joint Research Centre 667302, Alicia Koplowitz Foundation, ERDF (FEDER in Spanish) B-CTS-355-UGR18, University of Granada, Plan Propio de Investigacion, Visiting Scholar grants, Junta de Andalucia, Unit of Excellence on Exercise, Nutrition and Health (UCEENS), European Commission SOMM17/6107/UGR, EXERNET Research Network on Exercise and Health DEP2005-00046/ACTI, High Council of Sports 09/UPB/19, Spanish Government FPU 14/06837 FPI-BES-2014-068829 FJC2018-037925-I FJCI-2014-19563 IJCI-2017-33642 RYC2019-027287-I FPU15/02645 FJCI-2017-33396 IJC2019-041916-I, National Agency for Research and Development (ANID)/BECAS Chile 72180543, Ramon Areces Foundation

This study aimed to analyze the associations of activity-rest pattern indicators with academic achievement, executive function, and intelligence and to explore whether these associations are mediated by the total gray matter volume among children with overweight/obesity. Ninety-five children (10 ± 1 year, 37 girls) with overweight/obesity (based on the World Obesity Federation body mass index cutoff points) were included in this cross-sectional study. Hip- and wrist-worn ActiGraph GT3X + accelerometers were used to assess the activity-rest pattern. Interdaily stability (IS), intradaily variability (IV), the mean value of the lowest 5 hours (L5), and the mean value of the maximum 10 hours (M10) of activity and their respective timing (TL5, TM10) were used as indicators of the activity-rest pattern throughout the day. Chronotype and social jetlag were used as indicators of circadian preference. Academic achievement, executive function, and intelligence were assessed with standardized tests. Gray matter volume was acquired by magnetic resonance imaging (MRI). IS was positively associated with executive function (β = 0.244, P = .014). IV was negatively associated with mathematics and academic applications (β: -0.211 to -0.238, P's ≤ .026). Later TM10 in the day was related to lower writing, academic skills, and intelligence (β: -0.229 to -0.271, P's ≤ .025). None of the associations found were mediated by gray matter volume. A non-fragmented and stable activity-rest pattern and earlier physical activity in the day were associated with better academic achievement, executive function, and intelligence in children with overweight/obesity. Further studies are required to corroborate or contrast our findings.

ObjectivesTo investigate the effects of exercise on intelligence, executive functions, academic performance and brain outcomes in children with overweight/obesity. In secondary analyses, we explored potential mediators and moderators of the exercise effects.MethodsA total of 109 children (8-11.9y) with overweight/obesity were randomized (intention-to-treat) and 90 (82.6%) completed the post-exercise evaluation and attended ≥70% of the exercise sessions (per-protocol). Participants in the control group continued with their usual routines and received lifestyle recommendations, whereas the exercise group attended 3 sessions/week of aerobic plus resistance training during 20 weeks. Intelligence, executive functions (cognitive flexibility, inhibition, working memory) and academic performance were assessed with standardized tests; and hippocampal volume with magnetic resonance imaging (MRI).ResultsIn per-protocol analyses, the exercise intervention improved intelligence and cognitive flexibility (medium-large effect sizes observed, 0.4-0.7 SDs). These main effects were consistent in intention-to-treat analyses and after multiple-testing correction. Moreover, we found a positive, small-magnitude (i.e., 0.2-0.3 SDs) effect of exercise on academic performance (total, mathematics and problem solving), which was partially mediated by cognitive flexibility. Inhibition, working memory, hippocampal volume, and other brain MRI outcomes studied were not affected by our exercise program. Our intervention increased cardiorespiratory fitness performance (0.4 SDs) and these changes in fitness mediated some of the effects. Effects were mostly consistent across the studied moderators, except for larger improvements for intelligence in boys compared to girls.ConclusionExercise positively impacts intelligence and cognitive flexibility during development in children with overweight/obesity, without changes in the structural and functional brain outcomes studied.Trial RegistrationClinicalTrials.gov Identifier: NCT02295072SUMMARY BOXWhat is already known on this topic-Pediatric obesity is associated not only with poorer physical health but also with poorer cognitive and brain development.-Previous exercise interventions have mostly focused on executive functions and other dimensions of cognition, yet is largely unknown the extent to which exercise can improve intelligence during childhood, and actually, at any period of life.-Studies integrating effects of exercise on behavioral and brain magnetic resonance outcomes in a single article are scarce.-A in-depth study of the exercise characteristics (mode) and intensity, potential compensatory/contamination effects and role of potential mediators and moderators of the exercise effects is warranted.What this study adds-A 20-week randomized controlled trial of exercise improved intelligence and cognitive flexibility in preadolescent children with overweight/obesity.-Moreover, we found a positive, small-magnitude effect of exercise on academic performance, which was partially mediated by cognitive flexibility.-Cardiorespiratory peak performance mediated some yet not all the exercise effects observed.-The structural and functional brain outcomes studied were not affected by participation in the exercise program.How this study might affect research, practice or policyOur investigation suggests that exercise can positively impact intelligence and cognitive flexibility during a sensitive period of brain development in childhood. This stimulus can positively affect academic performance, as shown in our study, indicating that an active lifestyle during preadolescent development may lead to more successful life trajectories. This is particularly important in children with overweight/obesity who are known to be at higher risk of poorer physical and brain health.

Objective This study aimed to 1) analyze the criterion validity of the Slaughter equations (Slg-Eq) and bioelectrical impedance analysis (BIA) to estimate body fat percentage (BFP) and fat mass index (FMI) at different degrees of obesity in children compared with dual-energy x-ray absorptiometry (DXA) and 2) determine their agreement over time. Methods Ninety-two children with overweight or obesity (10.0 [SD 1.2] years; 34.8% girls) participated in this 20-week study. Anthropometric, BIA, and DXA measurements were performed. Results Both Slg-Eq and BIA methods underestimated BFP and FMI against DXA, and the bias was markedly larger with BIA (mean absolute percentage error = 11% for Slg-Eq vs. 18%-21% for BIA); a larger underestimation was observed in girls compared with boys for Slg-Eq (P ≤ 0.001), and the observed underestimation in adiposity was reduced as weight status increased. Systematic errors were kept constant over time, so no large differences between methods were observed in the change in adiposity. Conclusions At the group level, Slg-Eq provides a more valid estimation of BFP and FMI than BIA. At the individual level, Slg-Eq shows larger estimation errors. The validity of these methods might differ in sex and weight status. Nevertheless, both methods seem to be valid for monitoring changes in adiposity.

RODRIGUEZ-AYLLON, M., I. ESTEBAN-CORNEJO, J. VERDEJO-ROMAN, R. L. MUETZEL, J. H. MIGUELES, J. MORAGONZALEZ, P. SOLIS-URRA, K. I. ERICKSON, C. H. HILLMAN, A. CATENA, H. TIEMEIER, and F. B. ORTEGA. Physical Activity, Sedentary Behavior, and White Matter Microstructure in Children with Overweight or Obesity. Med. Sci. Sports Exerc., Vol. 52, No. 5, pp. 1218–1226, 2020. 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.

Background Wearable technologies play an important role in measuring physical activity (PA) and promoting health. Standardized validation indices (i.e., accuracy, bias, and precision) compare performance of step counting wearable technologies in young people. Purpose To produce a catalog of validity indices for step counting wearable technologies assessed during different treadmill speeds (slow [0.8–3.2 km/h], normal [4.0–6.4 km/h], fast [7.2–8.0 km/h]), wear locations (waist, wrist/arm, thigh, and ankle), and age groups (children, 6–12 years; adolescents, 13–17 years; young adults, 18–20 years). Methods One hundred seventeen individuals (13.1 ± 4.2 years, 50.4% female) participated in this cross-sectional study and completed 5-min treadmill bouts (0.8 km/h to 8.0 km/h) while wearing eight devices (Waist: Actical, ActiGraph GT3X+, NL-1000, SW-200; Wrist: ActiGraph GT3X+; Arm: SenseWear; Thigh: activPAL; Ankle: StepWatch). Directly observed steps served as the criterion measure. Accuracy (mean absolute percentage error, MAPE), bias (mean percentage error, MPE), and precision (correlation coefficient, r; standard deviation, SD; coefficient of variation, CoV) were computed. Results Five of the eight tested wearable technologies (i.e., Actical, waist-worn ActiGraph GT3X+, activPAL, StepWatch, and SW-200) performed at P P > 0.05). Age did not have any effect (P > 0.05). Conclusions Standardized validation indices focused on accuracy, bias, and precision were cataloged by speed, wear location, and age group to serve as important reference points when selecting and/or evaluating device performance in young people moving forward. Reduced performance can be expected at very slow walking speeds (0.8 to 3.2 km/h) for all devices. Ankle-worn and thigh-worn devices demonstrated the highest accuracy. Speed and wear location had a significant effect on accuracy and bias, but not precision. Trial registration Clinicaltrials.govNCT01989104. Registered November 14, 2013.

Aim Physical activity (PA) has traditionally been measured wearing accelerometers on the hip, but they are increasingly being worn on the wrist. We compared hip and wrist accelerometers with regard to their acceptability and any associations between PA and fatness and fitness. Methods This cross-sectional study comprised 103 children aged 8-12 years (62% boys) who participated in the ActiveBrains trial by the University of Granada, Spain, in 2014-2016. The children wore both ActiGraph GT3X+ hip and wrist accelerometers round the clock for 7 days. The acceptability of both placements was evaluated by a questionnaire, while the children's fat mass index, waist circumference and cardiorespiratory fitness (CRF) were assessed. Results Wearing wrist accelerometers caused less disturbance, mainly because hip accelerometers caused more issues during the night. The measurements from both placements showed that lower PA levels were associated with fatness and that higher PA levels were associated with better CRF. Conclusion Both placements showed consistent results with regard to measuring associations between PA levels and fatness and fitness. However, wearing them on the wrist caused less discomfort at night. Future studies are needed to confirm the best placement for accelerometers during PA studies.

Low-intensity resistance training (LI-RT) combined with blood flow restriction (BFR) is an alternative to traditional moderate–high-intensity resistance training to increase strength and muscle mass. However, the evidence about the efficacy of this novel training method to increase strength and muscle mass in healthy and older adults with pathologies is limited. Furthermore, the possible risk and adverse effects with BFR training methodology in older adults should be considered. (1) To summarize the current evidence on training with BFR strategies in older adults aiming to improve strength and to increase muscle mass; and (2) to provide recommendations for resistance and aerobic training with BFR in older adults based on the studies reviewed. Studies that investigated the chronic responses to resistance training or aerobic training with BFR related to strength and muscle mass changes in older adults were identified. Two independent researchers conducted the search in PubMed, Web of Science, and Google Scholar databases from their inception up to November 1, 2018. Seventeen out of 35 studies, which performed resistance or aerobic training with BFR in older adults focused on strength and muscle mass outcomes, were included in this review. Studies performing resistance and aerobic training with BFR found better improvements in strength and higher increase in muscle mass compared to non-BFR groups that performed the same training protocol. High-intensity resistance training (HI-RT) without BFR provided greater improvements in strength and a similar increase in muscle mass compared to light-intensity resistance training (LI-RT) with BFR. Current evidence suggests that LI-RT and/or aerobic training with BFR improves strength and increases muscle mass in older people. Light-intensity training without BFR would normally not obtain such benefits. Therefore, LI-RT and aerobic training with BFR is an alternative to traditional methods to improve strength and by way of an increase in muscle mass, which are important in the elderly who have progressive muscle atrophy and are at higher risk of falls.

INTRODUCTION: Chronic inflammation plays an important role on the pathogenesis of several cardiovascular and metabolic diseases, as well as on brain function and behaviour. The aim of the present study was to examine the associations between inflammatory biomarkers and a wide range of brain health indicators (i.e., academic performance, executive function, behavioural and emotional functioning, and brain volume) in children with overweight/obesity. METHODS: A total of 107 children (10.0 ± 1.1 years, 41% girls) from the ActiveBrains project were included in the analysis. Five inflammatory biomarkers were analysed in plasma: white blood cell (WBC) count, interleukin-6 (IL-6), interleukin-1beta, tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein (CRP). Academic performance was assessed by Woodcock-Munoz Tests of Achievement. Executive function was assessed through the Design Fluency Test for cognitive flexibility, the Stroop test for cognitive inhibition, and the Delayed Non-Match-to-Sample task for working memory. Behavioural and emotional functioning was evaluated through the Behavior Assessment System for Children (BASC) questionnaire. Total and regional brain volume was assessed by magnetic resonance imaging. RESULTS: IL-6 was inversely associated with adaptive skills (beta = -0.228; p = 0.030), while TNF-alpha was related to mathematics (beta = -0.198; p = 0.034). In addition, CRP was positively associated with externalizing (beta = 0.246; p = 0.046) and internalizing problems (beta = 0.234; p = 0.039), as well as the behavioural symptoms index (beta = 0.236; p = 0.047). However, these significant associations disappeared after multiple comparisons correction. Inflammatory biomarkers were not associated with executive function and total brain volumes. Regarding regional brain analyses, WBC was positively associated with gray matter volume in the left middle temporal gyrus (beta = 0.387; p

Soccer is a very popular team sport that involves a variety of physical actions, such as sprints, accelerations, sudden decelerations, and jumps, among others. Research has placed recreational soccer in a good position as a strategy to increase physical activity levels and promote health across the lifespan. In this regard, recreational (non-competitive) soccer promotes social interaction and has the potential to increase long-term adherence to physical activity, even in those without prior experience in this sport. In this narrative review, we address the effects of recreational soccer on various health outcomes across the lifespan (i.e., from childhood to the elderly years) in both sexes. In addition, the beneficial effects of recreational soccer for people with prevalent pathologies, such as hypertension, type II diabetes mellitus, and cancer, are discussed.

It is known that obesity is associated with biomechanical alterations during locomotor tasks, which is considered a potential risk factor for the development of musculoskeletal disorders (MSKD). However, the association of obesity with biomechanical alterations of walking in the early stages of life have not yet been systematically reviewed. Thus, this review aims to summarize the biomechanical characteristics of walking in children and adolescents with overweight/obesity (OW/OB) versus their normal-weight (NW) counterparts. PubMed and Web of Science were systematically searched until November 2018. We found strong and moderate evidence supporting biomechanical differences in the gait pattern of OW/OB with respect to NW. Based on strong evidence, the gait patterns of OW/OB present greater pelvis transversal plane motion, higher hip internal rotation, higher hip flexion, extension and abduction moments and power generation/absorption, greater knee abduction/adduction motion, and higher knee abduction/adduction moments and power generation/absorption. Based on moderate evidence, OW/OB walk with greater step width, longer stance phase, higher tibiofemoral contact forces, higher ankle plantarflexion moments and power generation, and greater gastrocnemius and soleus activation/forces. These biomechanical alterations during walking in OW/OB could play a major role in the onset and progression of MSKD. ispartof: OBESITY REVIEWS vol:20 issue:7 pages:1033-1044 ispartof: location:England status: published

Introduction: The objective of the present work is to investigate the prospective associations between physical fitness components (cardiorespiratory fitness, motor fitness, and muscular strength) and two domains of executive function (working memory and inhibitory control) in adolescents. Methods: A total of 422 Spanish adolescents (13.35 ± 1.54 years, at baseline) from the UP&DOWN study with assessments at baseline and at 2-year follow-up were included in the analysis. Physical fitness was assessed using the ALPHA Fitness Test Battery. Working memory was measured by the n-back task and inhibitory control by the go/no-go task. Relationships of physical fitness components with working memory and inhibitory control were examined using linear regression models, adjusted for confounders. Results: Higher baseline levels of the three physical fitness components (cardiorespiratory fitness, motor fitness, and muscular strength) individually predicted better performance on the working memory (βranged, from .159 to .207; all p < .012) and inhibitory control (βranged, from 0.168 to 0.263; all p < .004) tasks at the 2-year follow-up. Muscular strength was the only component associated with inhibitory control independent of the other 2 physical fitness components (β = 0.266; p = .005). Conclusions: All components of adolescents’ physical fitness at baseline were individually associated with better working memory and inhibitory control at 2-year follow-up. Specifically, our results revealed that muscular strength was the component showing the strongest association with executive function, and even the only fitness component associated with inhibitory control independent of the other fitness components. These findings may have important public health and educational implication, since promoting exercise programs that improve physical fitness, and particularly, muscular strength, may positively influence cognitive health., Spanish Government DEP 2010-21662-C04-00 CAS19/00265 RYC2019-027287-I, National Health and Medical Research Council (NHMRC) of Australia APP 1176885 Spanish Government IJC2018-038008-I

Background Heuristic cadence (steps/min) thresholds of ≥100 and ≥ 130 steps/min correspond with absolutely-defined moderate (3 metabolic equivalents [METs]; 1 MET = 3.5 mL O2·kg− 1·min− 1) and vigorous (6 METs) intensity, respectively. Scarce evidence informs cadence thresholds for relatively-defined moderate (≥ 64% heart rate maximum [HRmax = 220-age], ≥ 40%HR reserve [HRR = HRmax -HRresting, and ≥ 12 Rating of Perceived Exertion [RPE]); or vigorous intensity (≥ 77%HRmax, ≥ 60%HRR, and ≥ 14 RPE). Purpose To identify heuristic cadence thresholds corresponding with relatively-defined moderate and vigorous intensity in 21–60-year-olds. Methods In this cross-sectional study, 157 adults (40.4 ± 11.5 years; 50.6% men) completed up to twelve 5-min treadmill bouts, beginning at 0.5 mph and increasing by 0.5 mph. Steps were directly observed, HR was measured with chest-worn monitors, and RPE was queried in the final minute of each bout. Segmented mixed model regression and Receiver Operating Characteristic (ROC) curve analyses identified optimal cadence thresholds, stratified by age (21–30, 31–40, 41–50, and 51–60 years). Reconciliation of the two analytical models, including trade-offs between sensitivity, specificity, positive and negative predictive values, and overall accuracy, yielded final heuristic cadences. Results Across all moderate intensity indicators, the segmented regression models estimated optimal cadence thresholds ranging from 123.8–127.5 (ages 21–30), 120.2–126.0 (ages 31–40), 117.7–122.7 (ages 41–50), and 113.3–116.1 steps/min (ages 51–60). Corresponding values for vigorous intensity were 140.3–144.1, 139.6–142.6, 139.3–143.6, and 131.6–132.8 steps/min, respectively. ROC analysis estimated chronologically-arranged age groups’ cadence thresholds ranging from 114.5–118, 113.5–114.5, 104.6–112.9, and 103.6–106.0 across all moderate intensity indicators, and 124.5, 121.5, 117.2–122.2, and 113.0 steps/min, respectively, for vigorous intensity. Conclusions Heuristic cadence thresholds corresponding to relatively-defined moderate intensity for the chronologically-arranged age groups were ≥ 120, 120, 115, and 110 steps/min, regardless of the intensity indicator (i.e., % HRmax, %HRR, or RPE). Corresponding heuristic values for vigorous intensity indicators were ≥ 135, 130, 125, and 120 steps/min. These cadences are useful for predicting/programming intensity aligned with age-associated differences in physiological response to, and perceived experiences of, moderate and/or vigorous intensity. Trial registration Clinicaltrials.gov NCT02650258. Registered 24 December 2015.

Molina-Garcia, P, Mora-Gonzalez, J, Migueles, JH, Rodriguez-Ayllon, M, Esteban-Cornejo, I, Cadenas-Sanchez, C, Plaza-Florido, A, Gil-Cosano, JJ, Pelaez-Perez, MA, Garcia-Delgado, G, Vanrenterghem, J, and Ortega, FB. Effects of exercise on body posture, functional movement, and physical fitness in children with overweight/obesity. J Strength Cond Res 34(8): 2146-2155, 2020-This study aims to analyze whether a 13-week exercise program based on "movement quality" and "multi-games" can lead to simultaneous benefits to body posture, fundamental movements, and physical fitness of children with overweight/obesity. A total of 64 children (10.9 ± 1.3 years, 25.9 ± 3.8 kg·m, 38 girls and 26 boys) with overweight/obesity were assigned either to a 13-week exercise-based intervention group (IG) (n = 33) or to a control group (CG) (n = 31). Subjects underwent assessments of basic anthropometry (body mass and height), body posture (2-dimensional photogrammetry), fundamental movements (Functional Movement Screen), and physical fitness (1 repetition maximum [1RM] arm and leg press, and ALPHA test battery). After the exercise program, the IG reduced lower limb angle (high effect size: -0.82 SDs; p = 0.001) and plumb-tragus distance (low effect: -0.43 SDs; p = 0.002) in the sagittal plane and increased lower limb angle in the frontal plane (high effect: 0.82 SDs; p = 0.003) compared with the CG. The IG improved their performance in deep squat (p = 0.004), active straight leg raise (p < 0.001), 1RM arm (low effect: 0.46 SDs; p = 0.002), handgrip strength (medium effect: 0.53 SDs; p < 0.001), and standing long jump (medium effect: 0.59 SDs; p = 0.003), all compared with the CG. In conclusion, children with overweight/obesity who participated in our 13-week exercise program developed a better alignment of the head and lower limb, improved their performance in fundamental movements, and experienced global muscular strength gains compared with the peers who continued with their usual lives. Among other potential implications, these improvements could contribute to the prevention of musculoskeletal disorders associated with childhood obesity and could increase adherence by positioning these children in a better physical status to keep practicing exercise. ispartof: JOURNAL OF STRENGTH AND CONDITIONING RESEARCH vol:34 issue:8 pages:2146-2155 ispartof: location:United States status: published

BACKGROUND: Childhood obesity is known to negatively impact body posture with severe consequences for the musculoskeletal system. Physical performance could play a positive role in the body posture conformation of these children, but there is little evidence to date. RESEARCH QUESTION: Is physical performance (i.e., physical fitness and functional movement) associated with a better body posture in children with overweight/obesity (OW/OB)? If so, is physical performance more determinant than their obesity degree in the body posture conformation? METHOD: A total of 62 children with OW/OB (10.86 ± 1.25 years, 58 % girls) were included. BMI, physical fitness components (one-repetition-maximum (1RM) arms and leg press, and ALPHA test battery), functional movement quality (Functional Movement Screen™) and body posture (two-dimensional photogrammetry) were evaluated. RESULTS: Physical fitness components and functional movement were overall associated with a more aligned posture of the head, lumbar and thoracic spines and lower limb. BMI was associated with head protraction, thoracic hyperkyphosis, lumbar hyperlordosis and lower limb valgus. BMI was the best predictor of head and lumbar spine posture, cardiorespiratory fitness of lower limb posture in frontal plane, speed-agility of lower limb posture in the sagittal plane and functional movement of thoracic spine. SIGNIFICANCE: Our findings reveal that physical fitness and functional movement are associated with a better global body posture in children with OW/OB, and that in some musculoskeletal structures are even better predictors than their obesity degree. ispartof: GAIT & POSTURE vol:80 pages:331-338 ispartof: location:England status: published

A.P.-F. and J.M.A.: conception and design, statistical analysis, interpretation of data, writing paper. F.J.A.G. and F.M.A.: conducted experiments, analyzed and interpretation of data, feedback on the paper. J.M.G.: feedback on the paper. J.H.M., J.S., and F.B.O.: interpretation of data, feedback on the paper. All authors read and approved the final manuscript., Heart rate variability (HRV) is a valid and non-invasive indicator of cardiac autonomic nervous system functioning. Short-term HRV recordings (e.g., 10 min long) produce data that usually is manually processed. Researcher subjective decision-making on data processing could produce inter- or intraresearcher differences whose magnitude has not been previously quantified in three independent human cohorts. This study examines the inter- and intra-researcher reproducibility of HRV parameters (i.e., the influence of R–R interval selection by different researchers and by the same researcher in different moments on the quantification of HRV parameters, respectively) derived from short-term recordings in a cohort of children with overweight/obesity, young adults and middle-age adults. Participants were recruited from 3 different studies: 107 children (10.03 ± 1.13 years, 58% male), 132 young adults (22.22 ± 2.20 years, 33% males) and 73 middle-aged adults (53.62 ± 5.18 years, 48% males). HRV was measured using a Polar RS800CX heart rate monitor. The intraclass correlation coefficient (ICC) ranged from 0.703 to 0.989 and from 0.950 to 0.998 for inter-and intra-researcher reproducibility, respectively. Limits of agreement for HRV parameters were higher for the interresearcher processing compared with the intra-researcher processing. On average, the intraresearcher differences were 31%, 62%, and 80% smaller than the inter-researchers differences based on Coefficient of Variation in children, young and middle-aged adults, respectively. Our study provides the quantification of the inter-researcher and intra-researcher differences in three independent human cohorts, which could elicit some clinical relevant differences for HRV parameters. Based on our findings, we recommend the HRV data signal processing to be performed always by the same trained researcher and we postulate a development of algorithms for an automatic ECG selection., Spanish Ministry of Economy and Competitiveness DEP2013-47540 DEP2016-79512-R PTA 12264-I, Spanish Ministry of Education, Culture and Sport FPU 16/02760 FPU15/02645 FPU15/04059 FPU14/06837 FPU14/04172, Unit of Excellence on Exercise and Health (UCEES), EXERNET Research Network on Exercise and Health in Special Populations DEP2005-00046/ACTI, Unit of Excellence in Sport and Health (UCEES) - University of Granada, Junta de Andalucía, European Union (EU) SOMM17/6107/UGR

The present study aims (i) to examine the association of physical fitness components (i.e., cardiorespiratory fitness, speed-agility, and muscular fitness) with brain current source density during working memory; and (ii) to examine whether fitness-related current density was associated to working memory performance and academic achievement. Eighty-five children with overweight/obesity aged 8-11 years participated in this cross-sectional study. Physical fitness components were assessed using the ALPHA test battery. Electroencephalography recordings were performed during a Delayed Non-Match-to-Sample task that assessed working memory. Brain source analysis was carried out using sLORETA to estimate regional current source density differences between high and low (H-L) working memory loads. Academic achievement was measured by the Spanish version of the Woodcock-Johnson III test battery. The main results showed that higher cardiorespiratory fitness was associated with higher H-L current density differences in frontal, limbic, and occipital regions during encoding and maintenance task's phases (β≥0.412, p ≤ 0.019). A limbic area was further related to better working memory performance (β=0.267, p = 0.005). During retrieval, higher cardiorespiratory fitness was also associated with higher current density in temporal regions (β=0.265, p = 0.013), whereas lower muscular fitness was associated with higher current density in frontal regions (β=-0.261, p = 0.016). Our results suggest that cardiorespiratory fitness, but not speed-agility nor muscular fitness, is positively associated with brain current source density during working memory processes in children with overweight/obesity. Fitness-related current density differences in limbic regions were associated with better working memory.

Whereas numerous studies have investigated the relationship of cardiorespiratory fitness with inhibition and neuroelectric activity, the role of other physical fitness components and physical activity (PA) intensities in this relationship remain unclear, especially in children with obesity. Therefore, the purpose of this study was to investigate the association of physical fitness, PA, and sedentary time with inhibitory control and neuroelectric activity in children. Eighty-four children (8-11 years) with overweight or obesity performed the ALPHA battery to assess their physical fitness components (i.e., muscular strength, speed-agility, and cardiorespiratory fitness). PA and sedentary time were assessed from hip and nondominant wrist-worn accelerometers. Inhibitory control was evaluated using a flanker task, and expressed as reaction time (RT) and response accuracy. P3 amplitude and latency were recorded using electroencephalography. Higher speed-agility and cardiorespiratory fitness were associated with shorter RT and larger P3 amplitude on incongruent trials. Higher speed-agility was associated with shorter RT on congruent trials. Hip-assessed moderate and moderate-to-vigorous PA were associated with longer P3 latency across trials, and vigorous PA with larger P3 amplitude on incongruent trials. Our results provide initial evidence suggesting that not only cardiorespiratory fitness, but also speed-agility, are associated with inhibitory control and P3 amplitude, whereas no significant associations were observed for muscular strength. The associations between PA (moderate, vigorous and moderate to-vigorous) and neuroelectric activity were accelerometer location-dependent. Promoting PA programs that enhance the cardiorespiratory fitness and speed-agility will contribute to better understanding whether such health improvements benefit inhibitory control in youth with overweight or obesity.

PURPOSE: To investigate the effect of a 13-wk exercise program, based on "movement quality" and "multigames" work, on plantar pressure during walking in children with overweight/obesity (OW/OB). METHOD: Seventy children (10.8 ± 1.2 yr, 58.5% girls) with OW/OB, as defined by the World Obesity Federation, were assigned to either a 13-wk exercise program (intervention group [EG]; n = 39), or to a usual lifestyle control group (CG) (n = 31). Children underwent assessments of basic anthropometry (weight and height) and plantar pressure during walking before and after the intervention period, recording plantar surface area (cm), maximum force (N), and force-time integrals (N·s). RESULTS: After the 13-wk intervention period, the EG participants showed no significant change in total plantar surface area, while the CG participants experienced an increase in this variable (small effect size, -2.5 SD; P = 0.015). Compared with the GC participants, the EG participants showed a greater increase in the maximum force supported beneath the forefoot during walking at the end of the intervention period (small effect size, 0.33 SD; P = 0.012), specifically under the lateral and medial forefoot (both P < 0.05). Force-time changed similarly in both groups by the end of the intervention period (all regions P > 0.05). CONCLUSIONS: These results suggest the exercise program led to positive structural and functional changes in plantar pressure during walking. The increase in maximum force supported by the forefoot in the EG children might indicate a change toward a more normal foot rollover pattern and a more adult gait. ispartof: MEDICINE AND SCIENCE IN SPORTS AND EXERCISE vol:52 issue:3 pages:654-662 ispartof: location:United States status: published

BACKGROUND Children with overweight/obesity have poorer sleep and smaller gray matter volume (GMV) than normal-weight children. No studies have investigated the associations of objectively-assessed sleep and GMV in children with overweight/obesity, or their implications for academic and cognitive outcomes. OBJECTIVES To explore the associations of sleep behaviors with GMV in the whole brain and particularly the hippocampus as a region of interest independent of sedentary time (SED) and physical activity; and to assess whether GMV in the associated regions was related to academic achievement, executive function and intelligence quotient (IQ). METHODS Ninety-six children with overweight/obesity (10 ± 1 year) were included. Sleep behaviors were assessed with accelerometers. GMV was acquired by magnetic resonance imaging. Academic achievement, executive function and IQ were assessed with separate tests. Analyses were adjusted for sex, peak height velocity and parent education as well as SED and physical activity. RESULTS Earlier wake time, less time in bed, wakening after sleep onset (WASO) and WASO occurrences were associated with higher GMV in eight cortical brain regions (k:56-448, P's

Objective: To examine the effects of a gamification teaching program, including the use of a game-based mobile app on the cardiorespiratory fitness (CRF) levels of college students. Materials and Methods: This study included a total of 117 college students (20.1 ± 2.9 years). They belonged to two different class groups, one formed the intervention group (IG, n = 58) and another one the control group (CG, n = 59). IG college students followed a 16-week gamification teaching program focused on encouraging physical activity (PA) through a game-based mobile app. The program was named “$in TIME” and set in the “In Time” science fiction movie. Each student belonging to the IG had a countdown on their mobile app so they had to perform learning and PA challenges to gain time. Thus, they had to run or cycle 3 to 5 days per week to gain time of life. The CG followed a traditional teaching methodology instead. CRF was assessed preintervention and postintervention using the 20-meter shuttle run test (20mSRT). Results: The stages completed in 20mSRT and the estimated maximal oxygen consumption at postintervention were significantly different between groups (P

A correction to this paper has been published and can be accessed via a link at the top of the paper.

Recent studies investigated the association of cardiorespiratory ftness with white matter microstructure in children, yet little work has explored to what extent other components of physical ftness (i.e., muscular or motor ftness) are associated with white matter microstructure. Indeed, this association has not been previously explored in children with overweight/obesity who present a diferent white matter development. Therefore, we aimed to examine associations between physical ftness components and white matter microstructure in children with overweight/obesity. In total, 104 (10.04 ± 1.15 years old; 43 girls) children were included in this cross-sectional study. Physical ftness was assessed using the ALPHA-ftness test battery. Fractional anisotropy (FA) and mean difusivity were derived from difusion tensor imaging (DTI). No association was found between physical ftness and global DTI metrics (all P> 0.082). Within individual tracts, all associations became non-signifcant when analyses were adjusted for multiple comparisons. Using the voxel-wise approach, we identifed a small cluster in the left lateral frontal lobe where children with greater upper-body muscular ftness showed higher FA (PFWE-corrected = 0.042). Although our results cannot conclude physical ftness is related to white matter microstructure in children with overweight/obesity; those fndings indicate that the association of muscular ftness with white matter microstructure might be more focal on frontal areas of the brain, as opposed to global diferences., Spanish Ministry of Economy and Competitiveness DEP2013-47540 DEP2016-79512-R DEP2017-91544-EXP RTI2018-095284-J-100, European Union (EU), European Commission Joint Research Centre 667302, Alicia Koplowitz Foundation, University of Granada, Research and Knowledge Transfer Fund (PPIT) 2016, Excellence Actions Programme: Units of Excellence, Scientific Unit of Excellence on Exercise and Health (UCEES), Andalusian Regional Government, Regional Ministry of Economy, Knowledge, Entreprises and University, European Union (EU) SOMM17/6107/UGR, SAMID III network, RETICS - PN I+D+I 2017-2021 (Spain), Spanish Ministry of Education, Culture and Sport FPU14/06837 FPU 16/02760, Government of Andalusian, Integrated Territorial Initiative 2014-2020 for the province of Cadiz PI-0002-2017, Spanish Ministry of Science, Innovation and Universities FJCI-2017-33396

The aim of this study was to examine whether metabolically healthy overweight/obese children have greater global and regional gray matter volumes than their metabolically unhealthy peers. We further examined the association between gray matter volume and academic achievement, along with the role of cardiorespiratory fitness in these associations. A total of 97 overweight/obese children (10.0 &plusmn, 1.2 years) participated. We classified children as metabolically healthy/unhealthy based on metabolic syndrome cut-offs. Global and regional brain volumes were assessed by magnetic resonance imaging. Academic achievement was assessed using the Woodcock-Mu&ntilde, oz standardized test. Cardiorespiratory fitness was assessed by the 20 m shuttle run test. Metabolically healthy overweight/obese (MHO) children had greater regional gray matter volume compared to those who were metabolically unhealthy (MUO) (all p &le, 0.001). A similar trend was observed for global gray matter volume (p = 0.06). Global gray matter volume was positively related to academic achievement (&beta, = 0.237, p = 0.036). However, all the associations were attenuated or disappeared after adjusting for cardiorespiratory fitness (p &gt, 0.05). The findings of the present study support that metabolically healthy overweight/obese children have greater gray matter volume compared to those that are metabolically unhealthy, which is in turn related to better academic achievement. However, cardiorespiratory fitness seems to explain, at least partially, these findings.

The association between vitamin D [25(OH)D] and bone health has been widely studied in children. Given that 25(OH)D and bone health are associated with muscular fitness, this could be the cornerstone to understand this relationship. Hence, the purpose of this work was to examine if the relation between 25(OH)D and areal bone mineral density (aBMD) was mediated by muscular fitness in children with overweight/obesity. Eighty-one children (8-11 years, 53 boys) with overweight/obesity were included. Body composition was measured with dual energy X-ray Absorptiometry (DXA), 25(OH)D was measured in plasma samples and muscular fitness was assessed by handgrip and standing long jump tests (averaged z-scores were used to represent overall muscular fitness). Simple mediation analyses controlling for sex, years from peak height velocity, lean mass and season were carried out. Our results showed that muscular fitness z-score, handgrip strength and standing long jump acted as mediators in the relationship between 25(OH)D and aBMD outcomes (percentages of mediation ranged from 49.6% to 68.3%). In conclusion, muscular fitness mediates the association of 25(OH)D with aBMD in children with overweight/obesity. Therefore, 25(OH)D benefits to bone health could be dependent on muscular fitness in young ages., This study was supported by the Spanish Ministry of Economy and Competitiveness (Reference DEP2013-47540). This study takes place thanks to the additional funding from the University of Granada, UGR Research and Knowledge Transfer Fund (PPIT) 2016, Excellence actions: Units of Scientific Excellence; Scientific Unit of Excellence on Exercise and Health (UCEES) and the European Regional Development Funds (ERDF, ref. SOMM17/6107/UGR). In addition, this study was further supported by the SAMID III network, RETICS, funded by the PN I+D+I 2017-2021 (Spain), ISCIII-Sub-Directorate General for Research Assessment and Promotion and the European Regional Development Fund (ERDF) (Ref. RD16/0022). L.G-M is supported by a fellowship from “la Caixa” Foundation (ID 100010434) and the fellowship code is LCF/BQ/PR19/11700007. J.H.M. and J.M.-G. are supported by the Spanish Ministry of Education, Culture and Sport (FPU15/02645 and FPU14/06837, respectively).

Obesity, as compared to normal weight, is associated with detectable structural differences in the brain. To the best of our knowledge, no previous study has examined the association of physical fitness with gray matter volume in overweight/obese children using whole brain analyses. Thus, the aim of this study was to examine the association between the key components of physical fitness (i.e. cardiorespiratory fitness, speed-agility and muscular fitness) and brain structural volume, and to assess whether fitness-related changes in brain volumes are related to academic performance in overweight/obese children. A total of 101 overweight/obese children aged 8-11 years were recruited from Granada, Spain. The physical fitness components were assessed following the ALPHA health-related fitness test battery. T1-weighted images were acquired with a 3.0 T S Magnetom Tim Trio system. Gray matter tissue was calculated using Diffeomorphic Anatomical Registration Through Exponentiated Lie algebra (DARTEL). Academic performance was assessed by the Batería III Woodcock-Muñoz Tests of Achievement. All analyses were controlled for sex, peak high velocity offset, parent education, body mass index and total brain volume. The statistical threshold was calculated with AlphaSim and further Hayasaka adjusted to account for the non-isotropic smoothness of structural images. The main results showed that higher cardiorespiratory fitness was related to greater gray matter volumes (P 0.001, k = 64) in 7 clusters with β ranging from 0.493 to 0.575; specifically in frontal regions (i.e. premotor cortex and supplementary motor cortex), subcortical regions (i.e. hippocampus and caudate), temporal regions (i.e. inferior temporal gyrus and parahippocampal gyrus) and calcarine cortex. Three of these regions (i.e. premotor cortex, supplementary motor cortex and hippocampus) were related to better academic performance (β ranging from 0.211 to 0.352; all P 0.05). Higher speed-agility was associated with greater gray matter volumes (P 0.001, k = 57) in 2 clusters (i.e. the inferior frontal gyrus and the superior temporal gyrus) with β ranging from 0.564 to 0.611. Both clusters were related to better academic performance (β ranging from 0.217 to 0.296; both P 0.05). Muscular fitness was not independently associated with greater gray matter volume in any brain region. Furthermore, there were no statistically significant negative association between any component of physical fitness and gray matter volume in any region of the brain. In conclusion, cardiorespiratory fitness and speed-agility, but not muscular fitness, may independently be associated with greater volume of numerous cortical and subcortical brain structures; besides, some of these brain structures may be related to better academic performance. Importantly, the identified associations of fitness and gray matter volume were different for each fitness component. These findings suggest that increases in cardiorespiratory fitness and speed-agility may positively influence the development of distinctive brain regions and academic indicators, and thus counteract the harmful effect of overweight and obesity on brain structure during childhood.

(1) To examine the comparability, i.e., discriminatory power, in a preschooler test (PREFIT 20-m shuttle-run test) and the 20mSRT-Original in 5–6-year-olds; (2) to provide an equation to estimate VO2max from the 20mSRT-PREFIT. 138 participants aged 5–6 years performed the 20mSRT-PREFIT and the 20mSRT-Original in a counterbalanced order. Total test duration, completed stages, maximum speed and maximum heart rate were registered. Participants finished stages from 2–10 in the 20mSRT-PREFIT, whereas stages 1–5 were completed in the 20mSRT-Original and a null was registered, showing the original version a lower discriminatory power. We also observed that the higher the cardiorespiratory fitness level the more comparable were the tests, i.e., − 0.04 km h−1 difference between tests in the fittest participants (i.e., maximum speed ≥ 9.5 km h−1). Using the original equation proposed by Leger and colleagues in 1988 and based on the estimation regression of maximum speed in the 20mSRT-Original from the PREFIT version, we computed a new equation to estimate VO2max from the 20mSRT-PREFIT: Y = 44.657 + 1.795X 1 − 2.601X 2 + 0.0852X 1 X 2 (r = 0.77; r 2 = 0.59; SEE = 1.25 ml kg−1 min−1 or 2.59% of estimated mean VO2max = 48.38 ml kg−1 min−1), where X 1 is the 20mSRT-PREFIT maximum speed (km h−1) and X 2 is the age of participants. The 20mSRT-PREFIT resulted in a significantly higher maximum heart rate than the 20mSRT-Original. The 20mSRT-PREFIT has higher discriminatory power than the 20mSRT-Original. Our study provides for the first time an opportunity to estimate VO2max in preschoolers and children based on the 20mSRT-PREFIT maximum speed and the age of participants.

Objectives In childhood (>6 years-old) and adolescence, fitness testing is feasible, reliable and related to later health. The purpose of this study was to examine the feasibility and reliability of a field-based fitness-test battery in preschool children. Design Repeated measures. Methods A total of 161 preschoolers aged 3 to 5 years participated in the study. Anthropometry, cardiorespiratory fitness, muscular strength and motor fitness were tested twice (2 weeks apart) using weight, height, waist circumference, PREFIT 20 m shuttle run, handgrip strength, standing long jump, 4 × 10 m shuttle run and one-leg stance tests, respectively. Results The main results indicated that all tests are feasible and highly reliable (mean differences, weight = 0.04 kg, height = 0.22 cm, waist circumference = −0.08 cm, PREFIT 20 m shuttle run = 2.00 laps, handgrip strength = −0.24 kg and 4 × 10 m shuttle run = 0.12 s), in preschool children, except for the standing long jump test and one-leg stance test (mean differences of −7.31 cm and 8.01 s). After some methodological adaptations, reliability for standing long jump was improved in a replication study (i.e. from −7 to −2 cm). We observed evidence of heteroscedasticity in the 4 × 10 m shuttle run and one-leg stance tests. Conclusions The PREFIT battery is a feasible and reliable tool to assess physical fitness in preschool children yet standing long jump has shown mixed findings and requires further studies. The one-leg stance test showed poor reliability in our study and if confirmed by future studies, its use in 3 to 5 years-old would not be recommended. Future studies should consider the mean differences provide in this study to explain the changes in test performance.

Objectives To examine which inflammatory markers are associated with bone mass and whether this association varies according to muscular fitness in children with overweight/obesity. Methods Plasma interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), epidermal growth factor, vascular endothelial growth factor A (VEGF), and C-reactive protein were analyzed in 55 children aged 8–11 years. A muscular fitness score was computed. Bone mineral content (BMC) of the total body-less head (TBLH) and lumbar spine (LS) were assessed using dual-energy x-ray absorptiometry. Results IL-6 (β = −0.136) and VEGF (β = −0.099) were associated with TBLH BMC, while TNF-α (β = −0.345) and IL-1β (β = 0.212) were associated with LS BMC (P