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Background: Standardized validation indices (i.e., accuracy, bias, and precision) provide a comprehensive comparison of step counting wearable technologies. Purpose: To expand a previously published child/youth catalog of validity indices to include adults (21–40, 41–60 and 61–85 years of age) assessed across a range of treadmill speeds (slow [0.8–3.2 km/h], normal [4.0–6.4 km/h], fast [7.2–8.0 km/h]) and device wear locations (ankle, thigh, waist, and wrist). Methods: Two hundred fifty-eight adults (52.5 ± 18.7 years, 49.6% female) participated in this laboratory-based study and performed a series of 5-min treadmill bouts while wearing multiple devices; 21 devices in total were evaluated over the course of this multi-year cross-sectional study (2015–2019). The criterion measure was directly observed steps. Computed validity indices included accuracy (mean absolute percentage error, MAPE), bias (mean percentage error, MPE), and precision (correlation coefficient, r; standard deviation, SD; coefficient of variation, CoV). Results: Over the range of normal speeds, 15 devices (Actical, waist-worn ActiGraph GT9X, activPAL, Apple Watch Series 1, Fitbit Ionic, Fitbit One, Fitbit Zip, Garmin vivoactive 3, Garmin vivofit 3, waist-worn GENEActiv, NL-1000, PiezoRx, Samsung Gear Fit2, Samsung Gear Fit2 Pro, and StepWatch) performed at < 5% MAPE. The wrist-worn Acti‑ Graph GT9X displayed the worst accuracy across normal speeds (MAPE = 52%). On average, accuracy was compromised across slow walking speeds for all wearable technologies (MAPE = 40%) while all performed best across normal speeds (MAPE = 7%). When analyzing the data by wear locations, the ankle and thigh demonstrated the best accuracy (both MAPE = 1%), followed by the waist (3%) and the wrist (15%) across normal speeds. There were significant effects of speed, wear location, and age group on accuracy and bias (both p < 0.001) and precision (p ≤ 0.045). Conclusions: Standardized validation indices cataloged by speed, wear location, and age group across the adult lifespan facilitate selecting, evaluating, or comparing performance of step counting wearable technologies. Speed, wear location, and age displayed a significant effect on accuracy, bias, and precision. Overall, reduced performance was associated with very slow walking speeds (0.8 to 3.2 km/h). Ankle- and thigh-located devices logged the highest accuracy, while those located at the wrist reported the worst accuracy., United States Department of Health & Human Services National Institutes of Health (NIH) - USA NIH National Institute on Aging (NIA) 5R01AG049024

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.

Background In younger adults (i.e., those Purpose To establish heuristic (i.e., evidence-based, practical, rounded) cadence thresholds for absolutely-defined moderate (3 METs) and vigorous (6 METs) intensity in adults 41 to 60 years of age. Methods In this cross-sectional study, 80 healthy adults of middle-age (10 men and 10 women representing each 5-year age-group between 41 to 60 years; body mass index = 26.0 ± 4.0 kg/m2) walked on a treadmill for 5-min bouts beginning at 0.5 mph and increasing in 0.5 mph increments. Performance termination criteria included: 1) transitioning to running, 2) reaching 75% of age-predicted maximum heart rate, or 3) reporting a Borg rating of perceived exertion > 13. Cadence was directly observed (i.e., hand tallied). Intensity (i.e., oxygen uptake [VO2] mL/kg/min) was assessed with an indirect calorimeter and converted to METs (1 MET = 3.5 mL/kg/min). A combination of segmented regression and Receiver Operating Characteristic (ROC) modeling approaches was used to identify optimal cadence thresholds. Final heuristic thresholds were determined based on an evaluation of classification accuracy (sensitivity, specificity, positive and negative predictive value, overall accuracy). Results The regression model identified 101.7 (95% Predictive Interval [PI]: 54.9–110.6) and 132.1 (95% PI: 122.0–142.2) steps/min as optimal cadence thresholds for 3 METs and 6 METs, respectively. Corresponding values based on ROC models were 98.5 (95% Confidence Intervals [CI]: 97.1–104.9) and 117.3 (95% CI: 113.1–126.1) steps/min. Considering both modeling approaches, the selected heuristic thresholds for moderate and vigorous intensity were 100 and 130 steps/min, respectively. Conclusions Consistent with our previous report in 21 to 40-year-old adults, cadence thresholds of 100 and 130 steps/min emerged as heuristic values associated with 3 and 6 METs, respectively, in 41 to 60-year-old adults. These values were selected based on their utility for public health messaging and on the trade-offs in classification accuracy parameters from both statistical methods. Findings will need to be confirmed in older adults and in free-living settings.

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.

Background Heuristic (i.e., evidence-based, rounded) cadences of ≥100 and ≥ 130 steps/min have consistently corresponded with absolutely-defined moderate (3 metabolic equivalents [METs]) and vigorous (6 METs) physical activity intensity, respectively, in adults 21–60 years of age. There is no consensus regarding similar thresholds in older adults. Purpose To provide heuristic cadence thresholds for 3, 4, 5, and 6 METs in 61–85-year-old adults. Methods Ninety-eight community-dwelling ambulatory and ostensibly healthy older adults (age = 72.6 ± 6.9 years; 49% women) walked on a treadmill for a series of 5-min bouts (beginning at 0.5 mph with 0.5 mph increments) in this laboratory-based cross-sectional study until: 1) transitioning to running, 2) reaching ≥75% of their age-predicted maximum heart rate, or 3) reporting a Borg rating of perceived exertion > 13. Cadence was directly observed and hand-tallied. Intensity (oxygen uptake [VO2] mL/kg/min) was assessed with indirect calorimetry and converted to METs (1 MET = 3.5 mL/kg/min). Cadence thresholds were identified via segmented mixed effects model regression and using Receiver Operating Characteristic (ROC) curves. Final heuristic cadence thresholds represented an analytical compromise based on classification accuracy (sensitivity, specificity, positive and negative predictive value, and overall accuracy). Results Cadences of 103.1 (95% Prediction Interval: 70.0–114.2), 116.4 (105.3–127.4), 129.6 (118.6–140.7), and 142.9 steps/min (131.8–148.4) were identified for 3, 4, 5, and 6 METs, respectively, based on the segmented regression. Comparable values based on ROC analysis were 100.3 (95% Confidence Intervals: 95.7–103.1), 111.5 (106.1–112.9), 116.0 (112.4–120.2), and 128.6 steps/min (128.3–136.4). Heuristic cadence thresholds of 100, 110, and 120 were associated with 3, 4, and 5 METs. Data to inform a threshold for ≥6 METs was limited, as only 6/98 (6.0%) participants achieved this intensity. Conclusions Consistent with previous data collected from 21–40 and 41–60-year-old adults, heuristic cadence thresholds of 100, 110, and 120 steps/min were associated with 3, 4, and 5 METs, respectively, in 61–85-year-old adults. Most older adults tested did not achieve the intensity of ≥6 METs; therefore, our data do not support establishing thresholds corresponding with this intensity level. Trial registration Clinicaltrials.gov NCT02650258. Registered 24 December 2015.

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.

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

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

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

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 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.

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

To examine which inflammatory markers are associated with bone mass and whether this association varies according to muscular fitness in children with overweight/obesity.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.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 0.05). The interaction effect of muscular fitness showed a trend in the association of VEGF with TBLH BMC (P = 0.122) and TNF-α with LS BMC (P = 0.057). Stratified analyses by muscular fitness levels showed an inverse association of VEGF with TBLH BMC (β = -0.152) and TNF-α with LS BMC (β = -0.491) in the low-fitness group, while no association was found in the high-fitness group.IL-6, VEGF, TNF-α, and IL-1β are significantly associated with bone mass. Higher muscular fitness may attenuate the adverse effect of high VEGF and TNF-α on bone mass.

Trial registration: ClinicalTrials.gov identifier: NCT03894241 Date of register: March 28, 2019. Retrospectively Registered., Cogni-Action Project is supported and the study protocol was peer reviewed by the National Commission for Scientific and Technological Research CONICYT/FONDECYT INICIACION 2016 grant no. 11160703. PS-U was supported by a grant from CONICYT/BECAS Chile/72180543. IE-C is supported by a grant from the Spanish Ministry of Science and Innovation (IJCI-2017-33642). CC-S is supported by a grant from the Spanish Ministry of Economy and Competitiveness (BES-2014-068829). JHM and JMG are supported by the Spanish Ministry of Education, Culture and Sport (FPU15/ 02645, FPU14/06837, respectively). Funding bodies has no role in the design of the study and collection, analysis and interpretation of data and in writing the manuscript. This work is part of Ph.D. Thesis conducted in the Biomedicine Doctoral Studies of the University of Granada, Spain., Background: Education and health are crucial topics for public policies as both largely determine the future wellbeing of the society. Currently, several studies recognize that physical activity (PA) benefits brain health in children. However, most of these studies have not been carried out in developing countries or lack the transference into the education field. The Cogni-Action Project is divided into two stages, a cross-sectional study and a crossover-randomized trial. The aim of the first part is to establish the associations of PA, sedentarism, and physical fitness with brain structure and function, cognitive performance and academic achievement in Chilean schoolchildren (10–13 years-old). The aim of the second part is to determinate the acute effects of three PA protocols on neuroelectric indices during a working memory and a reading task. Methods: PA and sedentarism will be self-reported and objectively-assessed with accelerometers in a representative subsample, whilst physical fitness will be evaluated through the ALPHA fitness test battery. Brain structure and function will be assessed by magnetic resonance imaging (MRI) in a randomized subsample. Cognitive performance will be assessed through the NeuroCognitive Performance Test, and academic achievement by school grades. In the second part 32 adolescents (12–13 year-old) will be cross-over randomized to these condition (i) “Moderate-Intensity Continuous Training” (MICT), (ii) “Cooperative High-Intensity Interval Training” (C-HIIT), and (iii) Sedentary condition. Neuroelectric indices will be measures by electroencephalogram Discussion: The main strength of this project is that, to our knowledge, this is the first study analysing the potential association of PA, sedentarism, and physical fitness on brain structure and function, cognitive performance, and academic achievement in a developing country, which presents an important sociocultural gap. For this purpose, this project will use advanced technologies in neuroimaging (MRI), electrophysiology (EEG), and eye-tracking, as well as objective and quality measurements of several physical and cognitive health outcomes. Trial registration: ClinicalTrials.gov identifier: NCT03894241 Date of register, National Commission for Scientific and Technological Research CONICYT/FONDECYT INICIACION 2016 grant no. 11160703, Grant from CONICYT/BECAS Chile/72180543, Spanish Ministry of Science and Innovation (IJCI-2017-33642), Spanish Ministry of Economy and Competitiveness (BES-2014-068829)

This study aimed to investigate the independent and combined associations between several fatness indicators and fitness components with functional movement quality in overweight/obese children. A total of 56 children (33 girls, aged 8-12) classified as overweight/obese according to the World Obesity Federation standard cut points, participated in this study. Participants underwent assessments of fatness [body mass index (BMI), waist circumference, and bioelectrical impedance measures], fitness [1 repetition maximum bench and leg press, and ALPHA test battery], and functional movement quality [4 tests from Functional Movement Screen TM (FMS)]. All fatness outcomes, except waist circumference, were negatively associated with total FMS score, after controlling for cardiorespiratory fitness. Cardiorespiratory fitness, lower limbs muscle strength, and speed-agility were positively associated with the total FMS score, regardless of BMI. Our results suggest that children with greater fatness indicators demonstrate lower functional movement quality independently of their fitness level, whereas children with better fitness level (i.e. cardiorespiratory fitness, lower limbs muscular strength, and speed-agility) demonstrate greater functional movement quality independently of their fatness level. However, children´s weight status seems to be more determinant than their fitness level in terms of functional movement quality, whereas being fit seems to moderately attenuate the negative influence of fatness. ispartof: JOURNAL OF SPORTS SCIENCES vol:37 issue:8 pages:878-885 ispartof: location:England status: published

To examine whether areal bone mineral density (aBMD) differs between metabolically healthy (MHO) and unhealthy (MUO) overweight/obese children and to examine the role of moderate-to-vigorous physical activity (MVPA) and cardiorespiratory fitness (CRF) in this association.A cross-sectional study was developed in 188 overweight/obese children (10.4 ± 1.2 years) from the ActiveBrains and EFIGRO studies. Participants were classified as MHO or MUO based on Jolliffe and Janssen's metabolic syndrome cut-off points for triglycerides, glucose, high-density cholesterol and blood pressure. MVPA and CRF were assessed by accelerometry and the 20-m shuttle run test, respectively. Body composition was measured by dual-energy X-ray absorptiometry.In model 1 (adjusted for sex, years from peak high velocity, stature and lean mass), MHO children had significantly higher aBMD in total body less head (Cohen's d effect size, ES = 0.34), trunk (ES = 0.43) and pelvis (ES = 0.33) than MUO children. These differences were attenuated once MVPA was added to model 1 (model 2), and most of them disappeared once CRF was added to the model 1 (model 3).This novel research shows that MHO children have greater aBMD than their MUO peers. Furthermore, both MVPA and more importantly CRF seem to partially explain these findings.

Objectives: To examine whether areal bone mineral density (aBMD) differs between metabolically healthy (MHO) and unhealthy (MUO) overweight/obese children and to examine the role of moderate-to-vigorous physical activity (MVPA) and cardiorespiratory fitness (CRF) in this association. Methods: A cross-sectional study was developed in 188 overweight/obese children (10.4 ± 1.2 years) from the ActiveBrains and EFIGRO studies. Participants were classified as MHO or MUO based on Jolliffe and Janssen’s metabolic syndrome cut-off points for triglycerides, glucose, high-density cholesterol and blood pressure. MVPA and CRF were assessed by accelerometry and the 20-m shuttle run test, respectively. Body composition was measured by dual-energy X-ray absorptiometry. Results: In model 1 (adjusted for sex, years from peak high velocity, stature and lean mass), MHO children had significantly higher aBMD in total body less head (Cohen’s d effect size, ES = 0.34), trunk (ES = 0.43) and pelvis (ES = 0.33) than MUO children. These differences were attenuated once MVPA was added to model 1 (model 2), and most of them disappeared once CRF was added to the model 1 (model 3). Conclusions: This novel research shows that MHO children have greater aBMD than their MUO peers. Furthermore, both MVPA and more importantly CRF seem to partially explain these findings. This study has been partially funded by the University of Granada, UGR Research and Knowledge Transfer Fund (PPIT) 2016, Excellence Actions Programme: Units of Scientific Excellence; Scientific Unit of Excellence on Exercise and Health (UCEES), and by the Regional Government of Andalusia, Regional Ministry of Economy, Knowledge, Enterprises and University and European Regional Development Fund (ERDF), ref. SOMM17/6107/UGR. The ActiveBrains study was funded by the Spanish Ministry of Economy and Competitiveness (Reference DEP2013-47540, DEP2016-79512-R, and DEP2017-91544-EXP). The EFIGRO study was funded by the Spanish Ministry of Health, 'Fondo de Investigación Sanitaria del Instituto de Salud Carlos III' (PI13/01335), 'Fondos Estructurales de la Unión Europea (FEDER), Una manera de hacer Europa,' and by the University of the Basque Country (GIU14/21). L.G.-M. is supported by 'La Caixa' Foundation within the Junior Leader fellowship programme (ID 100010434); M.M. is supported by the Spanish Ministry of Education, Culture and Sport (FPU14/03329) and EST17/00210; L.A. is supported by the Education Department of the Government of the Basque Country (PRE_2016_1_0057, PRE_2017_2_0224 and PRE_2018_2_0057); J.M.-G. and J.H.M. are supported by the Spanish Ministry of Education, Culture and Sport (FPU14/06837 and FPU15/02645, respectively).

This study examined (1) the association of dietary energy density from solid (EDS) and solid plus liquids (EDSL) with adiposity and cardiometabolic risk factors (CRF) in children with overweight and obesity, (2) the effect of under-reporting on the mentioned associations and (3) whether the association between ED and body composition and CRF is influenced by levels of physical activity. In a cross-sectional design, 208 overweight and obese children (8-12-year-old; 111 boys) completed two non-consecutive 24 h recalls. ED was calculated using two different approaches: EDS and EDSL. Under-reporters were determined with the Goldberg method. Body composition, anthropometry and fasting blood sample measurements were performed. Moderate to vigorous physical activity (MVPA) was registered with accelerometers (7-d-register). Linear regressions were performed to evaluate the association of ED with the previously mentioned variables. Neither EDS nor EDSL were associated with body composition or CRF. However, when under-reporters were excluded, EDS was positively associated with BMI (P=0 019), body fat percentage (P=0 005), abdominal fat (P=0 008) and fat mass index (P=0 018), while EDSL was positively associated with body fat percentage (P=0 008) and fat mass index (P=0 026). When stratifying the group according to physical activity recommendations, the aforementioned associations were only maintained for non-compliers. Cluster analysis showed that the low-ED and high-MVPA group presented the healthiest profile for all adiposity and CRF. These findings could partly explain inconsistencies in literature, as we found that different ED calculations entail distinct results. Physical activity levels and excluding under-reporters greatly influence the associations between ED and adiposity in children with overweight and obesity. The research leading to these results has received funding from la Caixa Foundation and Triptolemos Foundation, the Ministry of Health (FIS PI081297), the Research Network on Preventative Activities and Health Promotion (RD06/0018/ 0038), the Henning and Johan Throne-Holst Foundation (F. B. O.), the Spanish Ministry of Education, Culture and Sport (FPU14/03329 to M. M.), the Spanish Ministry of Economy and Competitiveness (DEP2013-47540 and DEP2016-78377-R; BES-2014-068829 to C. C.-S.), Fondo de Investigacion Sanitaria del Instituto de Salud Carlos III (PI13/01335), Fondos Estructurales de la Union Europea (FEDER), Una manera de hacer Europa, the Spanish Ministry of Science and Innovation (RYC-2011-09011 to F. B. O.), the University of Granada, Plan Propio de Investigacion 2016, Excellence Actions: Units of Excellence, Unit of Excellence on Exercise and Health (UCEES), Programa de Captacion de Talento - UGR Fellows (L. G.-M.), the SAMID III network, RETICS (PN I +D+ I 2017-2021). This study has been partially funded by the University of Granada, Plan Propio de Investigacion 2016, Excellence actions: Units of Excellence; Unit of Excellence on Exercise and Health (UCEES), and by the Junta de Andalucia, Consejeria de Conocimiento, Investigacion y Universidades and European Regional Development Fund (ERDF), reference SOMM17/6107/UGR. ISCIII-Sub-Directorate General for Research Assessment and Promotion, the European Regional Development Fund (RD16/ 0022), the EXERNET Research Network on Exercise and Health in Special Populations (DEP2005-00046/ACTI), and the University of the Basque Country (GIU14/21). J. M.-G. is supported by the Spanish Ministry of Education, Culture and Sport (FPU14/06837). J. H. M. is supported by the Spanish Ministry of Education, Culture and Sport (FPU15/02645).

This study aimed to analyse the association between socioeconomic status (SES) and fatness and fitness in preschoolers. 2,638 preschoolers (3-5 years old; 47.2% girls) participated. SES was estimated from the parental educational and occupational levels, and the marital status. Fatness was assessed by body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR). Physical fitness components were assessed using the PREFIT battery. Preschoolers whose parents had higher educational levels had lower fatness (P 0.05). BMI significantly differed across occupational levels of each parent (P 0.05) and WHtR across paternal levels (P = 0.004). Musculoskeletal fitness was different across any SES factor (P 0.05), except handgrip across paternal occupational levels (P ≥ 0.05). Preschoolers with high paternal occupation had higher speed/agility (P = 0.005), and those with high or low maternal education had higher VO

The aim of the present study was to examine the associations of physical fitness, sedentary time, and physical activity (PA) with working memory and neuroelectric activity in children with overweight/obesity. Seventy-nine children with overweight/obesity (10.2 ± 1.1 years old) participated in this cross-sectional study. We assessed physical fitness components (ie, muscular strength, speed agility, and cardiorespiratory fitness) using the ALPHA battery. Sedentary time and PA were assessed by GT3X+accelerometers (ActiGraph). Working memory was assessed using the delayed non-matched-to-sample task; mean reaction time (RT) and response accuracy were registered. Neuroelectric activity (ie, P3 amplitude and latency) was registered using the ActiveTwo System of BioSemi electroencephalogram. Higher upper-limb absolute strength was associated with lower response accuracy (P = 0.023), while higher lower-limb relative-to-weight strength was associated with larger P3 amplitude (P < 0.05). Higher speed agility and cardiorespiratory fitness levels were associated with shorter mean RT and larger P3 amplitude, and speed agility was also associated with shorter P3 latency (all P < 0.05). Vigorous PA was associated with larger P3 amplitude (P < 0.05). No associations were found for sedentary time or the rest of PA intensities (P ≥ 0.05). In addition to cardiorespiratory fitness, muscular strength and speed agility are also associated with working memory and neuroelectric activity in children with overweight/obesity. The association between PA and working memory is intensity-dependent, as significant findings were only observed for vigorous PA. Randomized controlled trials in this population would help to better understand whether improvements in different components of fitness and PA lead to better working memory and underlying brain function.

To examine the associations of physical fitness and physical activity with executive function in children with overweight and obesity.A cross-sectional study involving 100 children with overweight and obesity (10.1 ± 1.1 years old; 58.0% boys). We assessed physical fitness components (ie, muscular strength, speed-agility, and cardiorespiratory fitness) using the ALPHA battery, and physical activity and sedentary time by accelerometry. Cognitive flexibility was measured by the Design Fluency Test and Trail Making Test, inhibition by the Stroop test, and planning ability by the Zoo Map Test.Handgrip strength was positively associated with planning ability (P = .025). Speed-agility was positively related to cognitive flexibility and inhibition (P .05). Cardiorespiratory fitness and an overall fitness Z-score were positively associated with indicators of cognitive flexibility (P .05). No associations were found for physical activity and sedentary time with executive function (P ≥ .05).Muscular strength, speed agility, and cardiorespiratory fitness are associated with executive function in children with overweight and obesity. Cognitive flexibility seems to be more robustly associated with all fitness components, whereas planning ability and inhibition might depend on the component analyzed. The positive associations found in the present study in children with overweight and obesity call for more exercise-based randomized controlled trials in this population.

Early life factors may influence brain and academic outcomes later in life, especially during childhood. Here we investigate the associations of early life factors (i.e., birth weight, birth length, and breastfeeding) with gray matter volume, adjusted for body mass index and cardiorespiratory fitness, and ii) we test whether early-life factor-related differences in gray matter volume are associated with academic performance in overweight/obese children. 96 children with overweight/obesity aged 8-11 years participated. Birth weight, birth length and gestational age were collected from birth records, and breastfeeding practices were asked to parents. T1-weighted images were acquired with a 3.0 T Magnetom Tim Trio system. Academic performance was assessed with the Bateria III Woodcock-Muñoz Tests of Achievement. Whole-brain voxel-wise multiple regressions were used to test the associations of each early life factor with gray matter volume. Higher birth weight and birth length were associated with greater gray matter volume in 9 brain regions including the middle frontal gyrus, rectal gyrus, thalamus, putamen, middle temporal gyrus, lingual gyrus, middle occipital gyrus, calcarine cortex and cerebellum bilaterally (β ranging from 0.361 to 0.539, t ranging from 3.46 to 5.62 and cluster size from 82 to 4478 voxels; p 0.001); and greater duration of any breastfeeding was associated with greater gray matter volume in 3 regions including the bilateral inferior frontal gyrus and rolandic operculum (β ranging from 0.359 to 0.408, t ranging from 4.01 to 4.32 and cluster size from 64 to 171 voxels; p 0.001). No associations were found for duration of exclusive breastfeeding. Additionally, none of the gray matter regions that were associated with the early life factors were associated with academic performance (all p 0.05). Our results demonstrate that birth weight, birth length, and breastfeeding are predictive of gray matter volume of numerous brain structures that are involved in higher order cognition and emotion regulation, but how these results relate to measures of academic achievement remain a matter of speculation.

This study aimed to compare estimations of sedentary time (SED) and time spent in physical activity (PA) intensities in children with overweight/obesity across different age-appropriate cut-points based on different body-worn attachment sites and acceleration metrics. A total of 104 overweight/obese children (10.1 ± 1.1 years old, 43 girls) concurrently wore ActiGraph GT3X+ accelerometers on their right hip and non-dominant wrist for 7 days (24 hours). Euclidean norm -1 g (ENMO) and activity counts from both vertical axis (VACounts) and vector magnitude (VMCounts) were derived. We calculated estimates of SED and light, moderate, vigorous, and moderate-to-vigorous (MVPA) intensity PA using different published cut-points for children. The prevalence of children meeting the recommended 60 min/d of MVPA was calculated. The time spent in SED and the different PA intensities largely differed across cut-points based on different attachment sites and acceleration metrics (ie, SED = 11-252 min/d; light PA = 10-217 min/d; moderate PA = 1-48 min/d; vigorous PA = 1-35 min/d; MVPA = 4-66 min/d). Consequently, the prevalence of children meeting the recommended 60 min/d of MVPA varied from 8% to 96% of the study sample. The present study provides a comprehensive comparison between available cut-points for different attachment and acceleration metrics in children. Furthermore, our data clearly show that it is not possible (and probably will never be) to know the prevalence of meeting the PA guidelines based on accelerometer data since apparent differences range from almost zero to nearly everyone meeting the guidelines.

Cortical thickness and surface area are thought to be genetically unrelated and shaped by independent neurobiological events suggesting that they should be considered separately in morphometric analyses. Although the developmental trajectories of cortical thickness and surface area may differ across brain regions and ages, there is no consensus regarding the relationships of physical fitness with cortical thickness and surface area as well as for its subsequent influence on intelligence. Thus, this study examines: (i) the associations of physical fitness components (i.e., cardiorespiratory fitness, speed-agility and muscular fitness) with overall and regional cortical thickness and surface area; (ii) whether body composition indicators (i.e., body mass index, fat-free mass index and fat mass index) mediate these associations; and (iii) the association of physical fitness and cortical thickness with intelligence in overweight/obese children. A total of 101 overweight/obese children aged 8–11 years were recruited in 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 Tesla Siemens Magnetom Tim Trio system. We used FreeSurfer software version 5.3.0 to assess cortical thickness (mm) and surface area (mm2). The main results showed that cardiorespiratory fitness and speed-agility were related to overall cortical thickness (β = 0.321 and β = 0.302, respectively; both P 0.05). The associations of cardiorespiratory fitness and speed-agility with overall cortical thickness were mediated by fat mass index (56.86% & 62.28%, respectively). In conclusion, cardiorespiratory fitness and speed-agility, but not muscular fitness, are associated with overall cortical thickness, and in turn, thicker brain cortex is associated with higher intelligence in overweight/obese children. Yet, none of the three physical fitness components were related to surface area. Importantly, adiposity may hinder the benefits of cardiorespiratory fitness and speed-agility on cortical thickness. Understanding individual differences in brain morphology may have important implications for educators and policy makers who aim to determine policies and interventions to maximize academic learning and occupational success later in life.

(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 VO138 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 hThe 20mSRT-PREFIT has higher discriminatory power than the 20mSRT-Original. Our study provides for the first time an opportunity to estimate VO

Accelerometers are widely used to measure sedentary time, physical activity, physical activity energy expenditure (PAEE), and sleep-related behaviors, with the ActiGraph being the most frequently used brand by researchers. However, data collection and processing criteria have evolved in a myriad of ways out of the need to answer unique research questions; as a result there is no consensus. The purpose of this review was to: (1) compile and classify existing studies assessing sedentary time, physical activity, energy expenditure, or sleep using the ActiGraph GT3X/+ through data collection and processing criteria to improve data comparability and (2) review data collection and processing criteria when using GT3X/+ and provide age-specific practical considerations based on the validation/calibration studies identified. Two independent researchers conducted the search in PubMed and Web of Science. We included all original studies in which the GT3X/+ was used in laboratory, controlled, or free-living conditions published from 1 January 2010 to the 31 December 2015. The present systematic review provides key information about the following data collection and processing criteria: placement, sampling frequency, filter, epoch length, non-wear-time, what constitutes a valid day and a valid week, cut-points for sedentary time and physical activity intensity classification, and algorithms to estimate PAEE and sleep-related behaviors. The information is organized by age group, since criteria are usually age-specific. This review will help researchers and practitioners to make better decisions before (i.e., device placement and sampling frequency) and after (i.e., data processing criteria) data collection using the GT3X/+ accelerometer, in order to obtain more valid and comparable data. CRD42016039991.

Aim Physical activity has numerous benefits for children when it comes to academic achievements. This study determined whether active commuting – walking or cycling – to school, as a way of increasing total physical activity levels, was associated with academic achievements in students aged seven to 18 years. Methods A total of 2138 students participated in the study, which took place in the 2012/2013 academic year in three Spanish cities. We used a self-reported questionnaire to assess how the students travelled to and from school and their final school grades. Results We enrolled 489 primary schoolchildren and 1649 secondary schoolchildren, with similar numbers of boys and girls. The primary schoolchildren who travelled to school by motorbike, car or bus had better grades for all the selected school subjects (p ≤ 0.009) than those who walked or cycled. No significant associations were found for secondary schoolchildren, except for mathematics and their grade point averages. All models were adjusted for sex, age and school. Conclusion Active commuting to school was inversely associated with academic achievement in primary school students but not those at secondary school. Longitudinal and intervention studies are needed to further understand our findings.

The new and recent advances in neuroelectric and neuroimaging technologies provide a new era for further exploring and understanding how brain and cognition function can be stimulated by environmental factors, such as exercise, and particularly to study whether physical exercise influences brain development in early ages. The present study, namely the ActiveBrains project, aims to examine the effects of a physical exercise programme on brain and cognition, as well as on selected physical and mental health outcomes in overweight/obese children. A total of 100 participants aged 8 to 11 years are randomized into an exercise group (N=50) or a control group (N=50). The intervention lasts 20-weeks, with 3-5 sessions per week of 90 min each, and is mainly focused on high-intensity aerobic exercise yet also includes muscle-strengthening exercises. The extent to what the intervention effect remains 8-months after the exercise programme finishes is also studied in a subsample. Brain structure and function and cognitive performance are assessed using structural and functional magnetic resonance imaging and electroencephalographic recordings. Secondary outcomes include physical health outcomes (e.g. physical fitness, body fatness, bone mass and lipid-metabolic factors) and mental health outcomes (e.g. chronic stress indicators and overall behavioural and personality measurements such as anxiety or depression). This project will substantially contribute to the existing knowledge and will have an impact on societies, since early stimulation of brain development might have long lasting consequences on cognitive performance, academic achievement and in the prevention of behavioural problems and the promotion of psychological adjustment and mental health. Clinical trials. Gov identifier: NCT02295072.

We investigated whether there is an optimal grip span for determining the maximum handgrip strength in preschool children and if it is influenced by gender, age, or hand size. A total of 292 preschool children (3–5 years; 59.2% boys) carried out the handgrip strength test with different grip spans (4.0, 4.5, 5.0, 5.5, and 6.0 cm). The hand size was also measured. We also determined the reliability of the optimal grip span in another group of children ( n = 56, 57% boys) who did the test twice, with a 3-hour difference between tests. The results showed that 4.0 cm is the optimal grip span to determine the maximum handgrip strength in preschool children. This result applied to both genders, all age groups, and hand sizes. Paired t-tests showed no significant differences between test and retest. These findings may guide clinicians and researchers in selecting the optimal grip span when measuring handgrip strength in preschool children. Level IV

Background: Best-practice early interventions to increase physical activity (PA) in children with overweight and obesity should be both feasible and evidence based. Walking is a basic human movement pattern that is practical, cost-effective, and does not require complex movement skills. However, there is still a need to investigate how much walking—as a proportion of total PA level—is performed by children who are overweight and obese in order to determine its utility as a public health strategy. Objective: This study aimed to (1) investigate the proportion of overall PA indicators that are explained by step-based metrics and (2) study step accumulation patterns relative to achievement of public health recommendations in children who are overweight and obese. Methods: A total of 105 overweight and obese children (mean 10.1 years of age [SD 1.1]; 43 girls) wore hip-worn accelerometers for 7 days. PA volumes were derived using the daily average of counts per 15 seconds, categorized using standard cut points for light-moderate-vigorous PA (LMVPA) and moderate-to-vigorous PA (MVPA). Derived step-based metrics included volume (steps/day), time in cadence bands, and peak 1-minute, 30-minute, and 60-minute cadences. Results: Steps per day explained 66%, 40%, and 74% of variance for counts per 15 seconds, LMVPA, and MVPA, respectively. The variance explained was increased up to 80%, 92%, and 77% by including specific cadence bands and peak cadences. Children meeting the World Health Organization recommendation of 60 minutes per day of MVPA spent less time at zero cadence and more time in cadence bands representing sporadic movement to brisk walking (ie, 20-119 steps/min) than their less-active peers. Conclusions: Step-based metrics, including steps per day and various cadence-based metrics, seem to capture a large proportion of PA for children who are overweight and obese. Given the availability of pedometers, step-based metrics could be useful in discriminating between those children who do or do not achieve MVPA recommendations., MINECO (Ministerio de Economia y COmpetitividad)/FEDER (Fondo Europeo de DEsarrollo Regional) DEP2013-47540 DEP2016-79512-R RYC-2011-09011, Spanish Ministry of Education, Culture and Sport FPU15/02645 FPU14/06837, Spanish Ministry of Economy and Competitiveness BES-2014-068829, European Union (EU) 667302, University of Granada, Plan Propio de Investigacion 2016, Excellence action: Units of Excellence University of Granada, Plan Propio de Investigacion 2016, Excellence action: Unit of Excellence on Exercise and Health (UCEES), Junta de Andalucia SOMM17/6107/UGR RD16/0022, Consejeria de Conocimiento, Investigacion y Universidades SOMM17/6107/UGR RD16/0022, European Union (EU) SOMM17/6107/UGR RD16/0022, SAMID III (red de SAlud Materno Infantil y Desarrollo) network, RETICS (REdes Tematicas de Investigacion Cooperativa en Salud) - PN (Plan Nacional) I+D+I (Investigacion + Desarrollo + Innovacion) 2017-2021 (Spain), ISCIII (Instituto de Salud Carlos III)-Sub-Directorate General for Research Assessment and Promotion DEP2005-00046/ACTI, EXERNET Research Network on Exercise and Health in Special Populations DEP2005-00046/ACTI, Intramural Research Program at the National Institute on Aging, USA