Evaluación de los dominios de la actividad física y los componentes de la condición física en niños de 4-5 años en un centro de salud / Assessment of physical activity domains and physical fitness components in 4-5 year old children in a health centre

Introducción: la falta de actividad física y el sedentarismo en niños se asocia con una mayor adiposidad, bajo nivel de aptitud cardiovascular y riesgo de enfermedades cardiovasculares. Sin embargo, cumplir con las recomendaciones de actividad física se relaciona con mejoras en la salud mental, disminución de la ansiedad y depresión, así como adopción de hábitos saludables. Objetivos: evaluar la relación entre los diferentes dominios de la actividad física y del sedentarismo, medidos de forma objetiva, y los componentes de la condición física en niños españoles de 4 y 5 años. Población y métodos: estudio transversal dentro del proyecto “Observatorio y programa de intervención de ejercicio físico y estilos de vida en familia para niños y niñas de 4 a 5 años en Atención Primaria” (https://observatorioactividadfisica.es). La condición física se evaluó con la batería PREFIT y la cantidad e intensidad de actividad física mediante un acelerómetro tri-axial GENEActiv durante 7 días consecutivos las 24 horas del día. Resultados: la muestra evaluada fue de 70 niños (38 niños y 32 niñas) con una media (intervalo de confianza [IC] del 95%) de 4,83 años. No se observaron diferencias significativas en la condición física entre niños y niñas. Los niños realizaron una actividad física de mayor intensidad y tiempo que las niñas. Además, se encontró una fuerte relación significativa entre los componentes de la condición física y los dominios de la actividad física. Conclusiones: estos hallazgos resaltan la importancia de promover estilos de vida activos desde temprana edad y la necesidad de programas de entrenamiento estructurado para reducir el sedentarismo y mejorar la condición física en esta población (AU)

Introduction: lack of physical activity and sedentary lifestyles in children are associated with increased adiposity, low cardiovascular fitness, and risk of cardiovascular disease. On the other hand, adherence to physical activity recommendations is associated with improvements in mental health, decreased anxiety and depression, and healthier habits.Objectives: to assess the relationship between different domains of physical activity and sedentary behaviour, measured objectively, and components of physical fitness in Spanish children aged 4 and 5 years.Population and methods: cross-sectional study within the project “Observatory and intervention programme on physical exercise and lifestyles in families for children aged 4 to 5 years in primary care” (https://observatorioactividadfisica.es). Physical fitness was assessed with the PREFIT battery. To measure the amount and intensity of physical activity, participants wore a GENEActiv triaxial accelerometer on the non-dominant hand for 7 consecutive days, 24 hours a day.Results: the study sample included 70 children (38 boys and 32 girls) with a mean age of 4.83 years (95% confidence interval [CI]). There were no significant differences in physical fitness between boys and girls, but we found differences in physical activity. Boys were physically active for longer durations and with higher intensity than girls. We also found a significant and strong association between the components of physical fitness and physical activity domains in children aged 4 and 5 years.Conclusions: these findings highlight the importance of promoting active lifestyles from an early age and the need for structured training programs to reduce sedentary behaviour and improve physical fitness in this population. (AU)

Centile reference curves of the ultrasound-based characteristics of the rectus femoris muscle composition in children at 4-11 years old.

Quantitative diagnostic ultrasound has been proposed as a way to characterize muscle structure, but there is a lack of normative data for children. This study aims to establish age-specific normal ranges for echo-intensity (EI), cross-sectional area (CSA), muscular thickness (MT), and subcutaneous adipose thickness (SAT) values of the rectus femoris muscle in typically developing children. The study recruited 497 children (288 boys and 209 girls) aged 4-10.9 years (mean age 7.39 years), and muscle parameters were measured using 2D B-mode ultrasound. Percentile values and reference curves were calculated using the Lambda, Mu, and Sigma method (LMS). The results showed small variation between measurements for boys compared to girls, with the most significant difference in EI, CSA, and MT values. EI decreased with age, with the most pronounced curve in boys. SAT increased in both sexes, with a slightly higher increase in girls after the age of 9.0 years. This study provides the first age-specific reference norms for the rectus femoris muscle architecture in children, and further research is needed to validate these curves and determine their clinical utility.

Associations between basic motor competencies and physical fitness in Spanish pre-schoolers: a cross-sectional study.

BACKGROUND: Basic motor competencies (BMC) play a vital role in child development and are a primary focus of physical education. However, there is a lack of research on BMC in preschool-aged children, making this study particularly significant. The present study aims to examine the relationship between BMC and physical fitness components in Spanish preschool children. METHODS: This cross-sectional study was conducted on 101 children (n = 52 boys, average age of 4.80 years) living in Pamplona, North Spain. Components of physical fitness (handgrip strength, standing long jump, speed-agility, and cardiorespiratory fitness) were assessed using the PREFIT Battery. Overall physical fitness was computed from the four selected fitness components separately for boys and girls. Higher z-scores values in physical fitness indicate better fitness performance. To assess BMC, the MOBAK KG test battery was applied (subscales of object control and self-movement). Sex, age, and body mass index were used as main confounders. RESULTS: After adjustment for confounding factors, the BMC was positively associated with single (z-scores) components and overall physical fitness sum of z-scores (R2 from 0.178 to 0.469, all P-values < 0.05). Additional percentile scores weakened the associations, but they still remained significant (R2 from 0.146 to 0.337, all P-values < 0.05). Compared with participants in the lowest tertile, those in the highest tertile of the MOBAK KG sum score, and in both object movement and self-movement test subscales had significantly higher scores in single fitness component (z-scores or percentile) and overall physical fitness sum of z-scores (all P for trend < 0.001). CONCLUSIONS: Our results revealed that higher BMC is associated with better physical fitness in Spanish preschool children. The findings emphasize the crucial role that basic motor competence plays in promoting physical activity in preschool children.

Gamified family-based health exercise intervention to improve adherence to 24-h movement behaviors recommendations in children: "3, 2, 1 Move on Study".

BACKGROUND: Evidence suggests that movement patterns, including physical activity, sedentary behavior, and sleep duration, throughout a 24-h period, have a significant impact on biological processes and health outcomes for both young and adult populations. However, 80% of adolescents worldwide are not sufficiently active, and many children do not meet international physical activity recommendations for their age. Thus, the aim of this study is to evaluate the impact of a 12-week gamified family-based health and exercise intervention on physical fitness, basic motor competencies, mental and behavioral health, and adherence to 24-h movement guidelines in children aged 4 to 5 years old. The study will evaluate changes in sedentary levels, physical fitness, basic motor competencies, mental and behavioral disorders, adherence to the exercise program, and compliance with physical activity recommendations. In addition, the aim of this protocol is to describe the scientific rationale in detail and to provide information about the study procedures. METHODS/DESIGN: A total of 80 children, aged 4 to 5 years old, will be randomly assigned in a 1:1 ratio to one of two groups: the exercise group and the routine care group. The exercise group will undergo a 12-week exercise intervention, followed by a 12-week follow-up period. On the other hand, the routine care group will undergo a 12-week period of routine care, followed by a 12-week follow-up control period. The exercise program will be implemented in a family setting and facilitated through a gamified web platform with online supervision, with the hypothesis that it will have a positive impact on physical fitness, anthropometric measures, basic motor competencies, and adherence to 24-h movement guidelines. DISCUSSION: The results of this study will provide valuable insights into the impact of a gamified, family-oriented health and exercise program on various aspects of health, including physical fitness, basic motor competencies, mental and behavioral well-being, and adherence to 24-h movement guidelines. The findings will contribute to closing the gap in current knowledge on the effectiveness of these types of interventions for children and their parents. These findings will also contribute to  the development of future guidelines for promoting physical activity in children who do not meet the World Health Organization's recommended levels. An online "3, 2, 1 Move on Study" is believed to increase accessibility, promoting health equity, and reducing economic barriers for all children and their families across diverse social groups. TRIAL REGISTRATION: Trial registration: NCT05741879 . Registered February 14, 2023, Version 1.

Prevalence of meeting all three 24-h movement guidelines and its correlates among preschool-aged children.

The aim of the present study was twofold: first, to determine the meeting all three 24-h movement guidelines in Colombian preschool-aged children, and second, to explore the associations between different socio-ecological correlates and the meeting of these guidelines. This was a cross-sectional study with data from the Encuesta Nacional de Situación Nutricional (ENSIN-2015) in Colombia, 2015-2016. The sample comprised 3002 low-income preschoolers (3-4 years old, 50.7% boys). Data on physical activity, screen time, and sleep time were collected using the Cuestionario para la Medición de Actividad Física y Comportamiento Sedentario, reported by their parents. In total, 18 potential correlates (individual, interpersonal, organizational, and community level) were analyzed. Backward binary logistic regression analysis was performed with the potential correlates as independent variables and meeting all three 24-h movement guidelines as dependent variables. The prevalence of preschoolers meeting all three 24-h movement guidelines or none was 4.8% and 16.6%, respectively. In the final model, boys (odds ratio [OR] = 1.87, 95% confidence interval [CI] 1.00-3.50) and those who do not have television in their bedroom (OR = 2.09, 95%CI 1.05-4.14) were more likely to meet all three 24-h movement guidelines compared to with girls and those who have television, respectively. In conclusion, strategies to promote adherence to all 24-h movement guidelines among low-income preschoolers are warranted, and should focus on actions considering the importance of sex and home environment changes to support these movement behaviors.

Twenty-four-hour movement guidelines during adolescence and its association with obesity at adulthood: results from a nationally representative study.

To determine the association between adherence to the 24-h movement guidelines during adolescence with obesity at adulthood 14 years later in a nationally representative cohort. We analyzed data from 6984 individuals who participated in Waves I (1994-1995) and IV (2008-2009) of the National Longitudinal Study of Adolescent Health (Add Health) in the USA. Obesity was defined by the International Obesity Task Force cut-off points at Wave I and adult cut-points at Wave IV (body mass index [BMI]≥30 kg/m2 and waist circumference [WC]≥102 cm in male and 88 cm in female). Physical activity, screen time and sleep duration were self-reported. Adolescents who met screen time recommendation alone (ß = -1.62 cm, 95%CI -2.68 cm to -0.56), jointly with physical activity (ß = -2.25 cm, 95%CI -3.75 cm to -0.75 cm), and those who met all three recommendations (ß = -1.92 cm, 95%CI -3.81 cm to -0.02 cm) obtained lower WC at Wave IV than those who did not meet any of these recommendations. Our results also show that meeting with screen time recommendations (IRR [incidence rate ratio] = 0.84, 95%CI 0.76 to 0.92) separately and jointly with physical activity recommendations (IRR = 0.86, 95%CI 0.67 to 0.97) during adolescence is associated with lower risk of abdominal obesity at adulthood. In addition, adolescents who met all 24-h movement recommendations had lower risk of abdominal obesity later in life (IRR = 0.76, 95%CI 0.60 to 0.97). CONCLUSION: Promoting the adherence to the 24-h movement guidelines from adolescence, especially physical activity and screen time, seems to be related with lower risk of abdominal obesity later in life, but not for BMI. WHAT IS KNOWN: • Some studies have shown a relationship between adherence to 24-h movement guidelines and adiposity or obesity markers in youth. However, most of these studies have a cross-sectional design or a short follow-up. WHAT IS NEW: • This is the first study which determined the association between adherence to the 24-h movement guidelines during adolescence with obesity at adulthood 14 years later in a nationally representative US cohort. • Meeting the 24-h movement guidelines from adolescence seems to be related with lower risk of abdominal obesity later in life, but not for body mass index.

Adherence to aerobic and muscle-strengthening activities guidelines: a systematic review and meta-analysis of 3.3 million participants across 32 countries.

OBJECTIVE: To estimate the global prevalence of meeting the WHO guidelines for both aerobic and muscle-strengthening activities (MSA) in populations aged ≥5 years, and whenever possible to explore this prevalence according to sociodemographic and lifestyle factors. DESIGN: A systematic review and meta-analysis. DATA SOURCES: Five databases were systematically searched for studies published from inception to September 2022. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Articles with representative samples aged ≥5 years reporting the prevalence of meeting both aerobic and MSA guidelines were included. RESULTS: Twenty-one studies comprising 3 390 001 individuals from 32 countries were included. Overall adherence to the aerobic and MSA guidelines was 17.12% (95% CI 15.42% to 18.88%) in adults ≥18 years (n=3 346 723). Among adolescents aged 12-17 years, adherence to both guidelines was 19.74% (95% CI 14.72% to 25.31%) (n=43 278). No studies reported data for children aged 5-11 years. Women, older age, low/medium education levels, underweight or obesity, and poor and moderate self-rated health were associated with lower adherence to the physical activity guidelines (p<0.001) among adults, although the prevalence remained very low in all cases. Subgroup analyses were not conducted with children and adolescents due to a lack of studies. CONCLUSIONS: Only one out of five adolescents and adults met the recommended combined aerobic and MSA guidelines. Large-scale public health interventions promoting both types of exercise are needed to reduce the associated burden of non-communicable diseases. PROSPERO REGISTRATION NUMBER: CRD42022338422.

Effects of exercise training on glycaemic control in youths with type 1 diabetes: A systematic review and meta-analysis of randomised controlled trials.

The aim of the study is to evaluate whether exercise interventions are associated with improved glycaemic control in children and adolescents with type 1 diabetes mellitus (T1DM), and to examine its relationship with the characteristics of the intervention (i.e. type, intensity, length, and duration of the sessions). Eligible criteria were randomised controlled trials of youth aged 6-18 years with T1DM, participating in an exercise-based intervention where glycaemic control is measured (i.e. glycated haemoglobin [HbA1c]). Pooled effect sizes (Hedges'g) were calculated using random-effects inverse-variance analyses. Fourteen studies enrolling 509 patients were analysed. Effect size was expressed as Hedges' g to correct for possible small sample bias. Overall, HbA1c levels in the exercise group (g = -0.38 95% confidence interval [CI], -0.66 to -0.11; mean difference [MD] = -0.62%) were reduced compared with the control group. Concurrent training (g = -0.63 95%CI, -1.05 to -0.21), high-intensity exercise (g = -0.43 95%CI, -0.83 to -0.03), interventions ≥24 weeks (g = -0.92 95%CI, -1.44 to -0.40), and sessions ≥60 minutes (g = -0.71 95%CI, -1.05 to -0.08) showed larger changes (MD = -0.66% to 1.30%). In conclusion, our study suggests that programmes longer than 24 weeks with at least 60 min/session of high-intensity concurrent exercise may serve as a supportive therapy to metabolic control in youth with T1DM.HighlightsExercise training has a moderate effect on the reduction of glycated haemoglobin (HbA1c) and insulin dose per day in youths with type 1 diabetes.Exercise training moderately increases cardiorespiratory fitness youths with type 1 diabetes.Reductions in HbA1c are stronger with high-intensity and concurrent training (i.e. aerobic and strength) interventions, and longer programmes.

A descriptive ranking of blood pressure and physical fitness of Latin-American ethnic schoolchildren.

BACKGROUND: There is a general lack of information about how insufficient physical activity impacts blood pressure and physical fitness in Latin-American ethnic minorities. AIMS: To describe the interactions between insufficient physical activity, blood pressure, and physical fitness outcomes in Latin-American schoolchildren of different ethnicity. METHODS: This was a prospective, international, multi-center, and cross-sectional study of three Latin-American countries involving schoolchildren from seven ethnic groups of Colombia (Tikuna, Nasa, Embera), Brazil (African, Mulato), and Chile (Mapuche), and also European schoolchildren from Brazil and Chile. Data were categorized based on whether participants were physically active (PA) or insufficient physical activity (iPA) using the WHO physical activity recommendations. The main outcomes were systolic (SBP), diastolic (DBP), and mean arterial (MAP) blood pressure, and scores for physical and cardiorespiratory fitness (CRF, by estimated V˙O2max), handgrip muscle strength (HGS), and standing long jump (SLJ). Secondary outcomes were anthropometric measures (weight, height, body mass index [BMI], waist circumference [WC], waist-to-height ratio), and body fat percentage (BF%, limited data by country). Primary and secondary outcomes were ranked. RESULTS: For both PA and iPA categories, significant interactions between ethnic groups were found concerning SBP/DBP (F(37.7), ES 0.08; F(51.5), ES 0.08), V˙O2max (F(37.7), ES 0.08; F(51.5), ES 0.08), HGS (F(33.8), ES 0.07; F(5.03), ES 0.04), and SLJ (F(64.3), ES 0.14; F(64.3), 0.14). In the iPA category, Mapuche schoolchildren were classified 1st (119.5; 81.5) with highest SBP/DBP and highest MAP (94.6 mmHg); Embera schoolchildren were classified 1st with lowest V˙O2max (33.7 mL/kg/min); and European schoolchildren were classified 1st (19.9 kg) with lowest HGS and SLJ (121.4 m) physical fitness. CONCLUSIONS: Under conditions of insufficient physical activity conditions, Mapuche schoolchildren had the most detrimental blood pressure, whereas Embera, Tikuna, and European schoolchildren had the lowest levels of physical fitness. These results serve to highlight the need for the early and appropriate promotion of physical activity based on ethnic differences in Latin-American schools.

Factors associated with meeting the WHO physical activity recommendations in pregnant Colombian women.

In the absence of medical contraindications, physical activity (PA) can offer health maternal and fetal health outcomes during pregnancy. However, most pregnant women may not consider PA to be feasible, suitable and safe. Hence, it is essential to determine the prevalence of pregnant women who meet the PA recommendations and the possible factors associated with that meeting, since it might be important from the perspective of pregnant women's health. The aim of the present study was to establish the prevalence of meeting the World Health Organization PA recommendations for Colombian pregnant women, as well as possible factors that may be associated with meeting that recommendations. A cross-sectional study including representative data from the National Nutritional Situation Survey (2015) in Colombia was performed. Data were collected in 2015-2016. From an initial sample of 1140 Colombian pregnant women, 702 participants with complete data were included in the final analysis. PA was assessed by self-reported information through the long version of the International Physical Activity Questionnaire. Several potential factors were analysed according to four levels of the socioecological model: the individual, interpersonal, organizational and community levels. The prevalence of Colombian pregnant women who met with the PA recommendations was 7.5%. Indigenous and Mestizo pregnant women showed lower probabilities of meeting the PA recommendations [Indigenous: OR 0.05, 95% CI (0.01-0.18); Mestizo: OR 0.12, 95% CI (0.06-0.22)] than Afro-Colombian participants. Additionally, participants who lived near green and safe spaces for PA were more likely to meet the PA recommendations [OR 2.30, 95% CI (1.06-4.79)] than those who did not live near green areas. In conclusion, a low percentage of Colombian pregnant women met the new PA recommendations. The associations found according to race/ethnicity and living near green and safe areas underline the presence of fundamental disparities associated with meeting PA recommendations.

Relationship between parents' and children's objectively assessed movement behaviours prior to and during the COVID-19 pandemic.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic could have provoked undesirable harmful effects on movement behaviours among children. OBJECTIVE: To compare levels of physical activity (PA), sedentary behaviour (SB), and sleep time in children prior to and during the COVID-19 pandemic (after the lockdown) and to determine the association between changes in moderate-to-vigorous PA (MVPA), total PA (TPA), SB, and sleep time between mothers and fathers with their children. METHODS: A total of 110 children (aged 4-7 years) and their parents (63 mothers and 52 fathers) wore GENEActiv accelerometers for 6 days (4 weekdays and 2 weekend days) prior to the pandemic and 1 year into the pandemic to assess SB, MVPA, TPA, and sleep time. RESULTS: Children performed more MVPA on weekdays (p = 0.002), had higher SB (p = 0.001), and slept fewer hours during the pandemic than before (p < 0.001). Likewise, children performed more weekend day MVPA and TPA (p < 0.001) during the pandemic, and slept less than prior to the pandemic (p = 0.002). On weekdays, an increase in mother's MVPA and TPA (categorized as tertiles) was associated with higher increased on MVPA (p = 0.030) and TPA in their children (p = 0.023), respectively. On weekends, an increase in mother's MVPA was also associated with higher increases in MVPA (p = 0.011) in their children. CONCLUSION: During the pandemic, children got more MVPA, more SB, and slept fewer hours than before. Changes in PA seem to be associated with mother's behaviours, especially during weekdays.

Associations between physical fitness components with muscle ultrasound parameters in prepuberal children.

BACKGROUND/OBJECTIVES: Muscle ultrasound is a convenient technique to visualize normal and pathological muscle tissue as it is non-invasive and real-time. This technique is related to several physical performance parameters and body composition components in adults; however, this relationship remains unexplored in early aged. We aimed to evaluate the association between physical fitness components with muscle ultrasound parameters in prepuberal children. METHODS: A sample of 282 prepuberal children aged 5-9 years (144 boys) participated in the study. A trained sonographer obtained six B-mode images from femoral rectus for muscle thickness, subcutaneous adipose tissue (SAT) and area of the muscle of interest, were captured, and muscle ultrasound parameters (echo-intensity: EI uncorrected, EI correct equations) and intramuscular adipose tissue (IMAT) were extracted. Lean muscle tissue has low EI, whereas intramuscular fat and connective tissue have high EI. Physical fitness components (cardiorespiratory fitness, upper and lower muscle strength, speed-agility, and overall fitness levels) were also evaluated. Children were categorized as fit or unfit for each specific fitness test. RESULTS: After adjustment for sex and age, higher physical fitness components and overall fitness (z-score) levels were negatively associated with EI, IMAT, and SAT (cardiorespiratory fitness ß range = -0.264 to -0.298; upper-muscular strength ß range = -0.389 to -0.457; and lower-muscular strength ß range = -0.202 to -0.279; and speed-agility ß range = -0.257 to -0.302). Children categorized as fit according to four physical fitness components had lower EI uncorrected, EI correct equation 1-2, IMAT, and SAT than unfit children for each respective tests (all Ps < 0.001). CONCLUSION: Physical fitness components are inversely associated with EI, IMAT, SAT after adjusting for potential confounders, including sex and age, in prepuberal children. The present study strengthens the idea that muscle and adiposity parameters is affected by physical fitness even from early childhood.

Residual Impact of Concurrent, Resistance, and High-Intensity Interval Training on Fasting Measures of Glucose Metabolism in Women With Insulin Resistance.

We sought to assess the residual effects (post 72-h training cessation) on fasting plasma glucose (FPG) and fasting insulin (FI) after 12-weeks of high-intensity interval training (HIIT), resistance training (RT), or concurrent training (CT) in women with insulin resistance (IR). We also aimed to determine the training-induced, post-training residual impact of CT. A total of adult 45 women (age 38.5±9.2years) were included in the final analysis and were assigned to a control (CG; n=13, BMI 28.3±3.6kg/m2), HIIT [n=14, BMI 28.6±3.6kg/m2, three sessions/wk., 80-100% of the maximum heart rate (HRmax)], RT [n=8, BMI 29.4±5.5kg/m2, two sessions/wk., 8-10 points of the modified Borg, corresponding to 20 to 50% range of one maximum repetition test (1RM)], or CT group (n=10, BMI 29.1±3.0kg/m2, three sessions/wk., 80-100% of HRmax, and 8-10 Borg, or 20 to 50% range of 1RM, to each HIIT and RT compounds), with the latter including both HIIT and RT regimens. Training interventions lasted 12-weeks. The main outcomes were FPG and FI measured at pre- and 24-h and 72-h post-training (FPG24h, FI24h, and FPG72h, FI72h, respectively). Secondary endpoints were body composition/anthropometry and the adiposity markers waist circumference (WC) and tricípital skinfold (TSF). The residual effects 72-h post-training [delta (∆)] were significantly poorer (all p<0.01) in the CT group (∆FPG72h+6.6mg/dl, η 2: 0.76) than in the HIIT (∆FPG72h+1.2mg/dl, η 2: 0.07) and RT (∆FPG72h+1.0mg/dl, η 2: 0.05) groups. These findings reveal that HIIT reduces FPG and RT reduces FI 24-h post-training; both exercise interventions alone have remarkably better residual effects on FPG and FI (post-72h) than CT in women with insulin resistance.

Physical Activity, Sedentary Behavior, Sleep and Self-Regulation in Spanish Preschoolers during the COVID-19 Lockdown.

BACKGROUND: A better understanding of the effects of the lockdown on lifestyle behaviors may help to guide the public health response to COVID-19 at a national level and to update the global strategy to respond COVID-19 pandemic. The aim of the study was to examine the effects of the COVID-19 lockdown on device-measured physical activity (PA), sedentary time, sleep and self-regulation; and to determine whether PA and sleep are related to self-regulation problems during the lockdown. METHODS: PA, sedentary time and sleep were assessed using accelerometry in the week in which the Spanish national state of alarm was declared (n = 21). Parents reported preschooler's self-regulation difficulties (internalizing and externalizing) before (n = 268) and during the lockdown (n = 157) by a validated questionnaire. RESULTS: Preschoolers showed a decrease in total PA (mean difference [MD] = -43.3 min per day, 95% CI -68.1 to -18.5), sleep efficiency (MD = -2.09%, 95% CI -4.12 to -0.05), an increase in sedentary time (MD = 50.2 min per day, 95% CI 17.1 to 83.3) internalizing (MD = 0.17, 95% CI 0.06 to 0.28) and externalizing (MD = 0.33, 95% CI 0.23 to 0.44) problems. Preschoolers who met the World Health Organization recommendations for PA had lower internalizing scores than non-active peers (MD = -1.28, 95% CI -2.53 to -0.03). CONCLUSIONS: Our findings highlight the importance of meeting PA recommendations to reduce psychosocial difficulties during a lockdown situation.

Consequences of Low Sleep Duration in Anthropometric and Body Composition Parameters of Chilean Preschoolers.

Reduced sleep duration in schoolchildren has been associated with poor health outcomes at the scholar level; however, there is little information on the effects of sleep loss on Chilean preschoolers. The aim of this study was to describe and compare cardiometabolic outcomes according with the sleep duration in Chilean preschoolers. A second aim was to identify potential risk outcomes (i.e., in odds ratios) for suffering anthropometric and body composition alterations related with participants' sleep duration. A total of 99 (n = 54 boys; n = 45 girls) preschoolers (mean age (95% CI) 3.1 (2.7, 3.4 years), mean weight 16.1 (15.5, 16.6 kg)) were included in this study. Sleep duration was assessed using standardized questionnaires with the parents. Socio-demographic parents' information, as well as anthropometric, nutritional, and handgrip strength outcomes in preschoolers were distributed by tertiles (T1; < 10 h, T2; 10 to < 11 h, and T3; ≥ 11 h) of sleep time. Children in the lowest tertile of sleep duration had significantly higher body mass indices (p = 0.036), weight-for-height Z-scores (p < 0.0001), waist-hip ratios (p = 0.041), and body fat in percent (p = 0.035) and kg (p = 0.044) compared to those in the top tertile. Low sleep duration was associated with significantly greater risks of overweight/obesity (OR 1.3 (0.9, 1.8)), low height (OR 1.2 (0.8, 1.6)), and increased BMI (OR 1.5 (0.4, 1.4)), but not with reductions in grip strength. Chilean preschoolers with low sleep duration showed higher cardiometabolic markers (anthropometric/body composition) and were more likely to be classified as obese than youth with longer sleep duration.

Association of Cardiorespiratory Fitness Levels During Youth With Health Risk Later in Life: A Systematic Review and Meta-analysis.

Importance: Although the associations between cardiorespiratory fitness (CRF) and health in adults are well understood, to date, no systematic review has quantitatively examined the association between CRF during youth and health parameters later in life. Objectives: To examine the prospective association between CRF in childhood and adolescence and future health status and to assess whether changes in CRF are associated with future health status at least 1 year later. Data Sources: For this systematic review and meta-analysis, MEDLINE, Embase, and SPORTDiscus electronic databases were searched for relevant articles published from database inception to January 30, 2020. Study Selection: The following inclusion criteria were used: CRF measured using a validated test and assessed at baseline and/or its change from baseline to the end of follow-up, healthy population with a mean age of 3 to 18 years at baseline, and prospective cohort design with a follow-up period of at least 1 year. Data Extraction and Synthesis: Data were processed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Random-effects models were used to estimate the pooled effect size. Main Outcomes and Measures: Anthropometric and adiposity measurements and cardiometabolic health parameters. Results: Fifty-five studies were included with a total of 37 563 youths (46% female). Weak-moderate associations were found between CRF at baseline and body mass index (r = -0.11; 95% CI, -0.18 to -0.04; I2 = 59.03), waist circumference (r = -0.29; 95% CI, -0.42 to -0.14; I2 = 69.42), skinfold thickness (r = -0.34; 95% CI, -0.41 to -0.26; I2 = 83.87), obesity (r = -0.15; 95% CI, -0.23 to -0.06; I2 = 86.75), total cholesterol level (r = -0.12; 95% CI, -0.19 to -0.05; I2 = 75.81), high-density lipoprotein cholesterol (HDL-C) level (r = 0.11; 95% CI, 0.05-0.18; I2 = 69.06), total cholesterol to HDL-C ratio (r = -0.19; 95% CI, -0.26 to -0.13; I2 = 67.07), triglyceride levels (r = -0.10; 95% CI, -0.18 to -0.02; I2 = 73.43), homeostasis model assessment for insulin resistance (r = -0.12; 95% CI, -0.18 to -0.06; I2 = 68.26), fasting insulin level (r = -0.07; 95% CI, -0.11 to -0.03; I2 = 0), and cardiometabolic risk (r = -0.18; 95% CI, -0.29 to -0.07; I2 = 90.61) at follow-up. Meta-regression analyses found that early associations in waist circumference (ß = 0.014; 95% CI, 0.002-0.026), skinfold thickness (ß = 0.006; 95% CI, 0.002-0.011), HDL-C level (ß = -0.006; 95% CI, -0.011 to -0.001), triglyceride levels (ß = 0.009; 95% CI, 0.004-0.014), and cardiometabolic risk (ß = 0.007; 95% CI, 0.003-0.011) from baseline to follow-up dissipated over time. Weak-moderate associations were found between change in CRF and body mass index (r = -0.17; 95% CI, -0.24 to -0.11; I2 = 39.65), skinfold thickness (r = -0.36; 95% CI, -0.58 to -0.09; I2 = 96.84), obesity (r = -0.21; 95% CI, -0.35 to -0.06; I2 = 91.08), HDL-C level (r = 0.05; 95% CI, 0.02-0.08; I2 = 0), low-density lipoprotein cholesterol level (r = -0.06; 95% CI, -0.11 to -0.01; I2 = 58.94), and cardiometabolic risk (r = -0.08; 95% CI, -0.15 to -0.02; I2 = 69.53) later in life. Conclusions and Relevance: This study suggests that early intervention and prevention strategies that target youth CRF may be associated with maintaining health parameters in later life.

Association between Exercise-Induced Changes in Cardiorespiratory Fitness and Adiposity among Overweight and Obese Youth: A Meta-Analysis and Meta-Regression Analysis.

The aim of this study was to determine the minimum change in cardiorespiratory fitness (CRF) required to reduce adiposity (percent body fat) in exercise programs for overweight and obese youth. Studies were identified through a systematic search of five databases. Studies were limited to randomized controlled trials (RCTs) of exercise training (e.g., aerobic, strength, concurrent) that assessed percent body fat and CRF for both exercise and control groups in overweight and obese children and adolescents. A series of meta-regressions were conducted to explore links between change in CRF (maximum oxygen consumption, ml/kg/min) and change in percent body fat. Twenty-three RCTs were included (n = 1790, 59% females). Meta-regression analysis suggested that increases of at least 0.38 mL/kg/min in CRF (p < 0.001) were considered to be a clinically important reduction of percent body fat (-2.30%, 95% confidence interval -3.02 to -1.58; p < 0.001; I2 = 92.2%). Subgroup analysis showed that increases of at least 0.17 mL/kg/min in CRF favored a reduction of percent body fat of -1.62% (95% confidence interval -2.04 to -1.20; p < 0.001; I2 = 69.9%). In conclusion, this change in CRF could be considered by pediatric researchers, youth fitness specialists, and health care providers to determine the effectiveness in body fat reductions through exercise.

Association of Physical Education With Improvement of Health-Related Physical Fitness Outcomes and Fundamental Motor Skills Among Youths: A Systematic Review and Meta-analysis.

Importance: Whether quality- or quantity-based physical education (PE) interventions are associated with improvement of health-related physical fitness outcomes and fundamental motor skills (FMSs) in children and adolescents is unknown. Objective: To examine the association of interventions aimed at optimizing PE in terms of quality (teaching strategies or fitness infusion) or quantity (lessons per week) with health-related physical fitness and FMSs in children and adolescents. Data Sources: For this systematic review and meta-analysis, studies were identified through a systematic search of Ovid MEDLINE, Embase, Cochrane Controlled Trials Registry, and SPORTDiscus databases (from inception to October 10, 2019) with the keywords physical education OR PE OR P.E. AND fitness AND motor ability OR skills. Manual examination of references in selected articles was also performed. Study Selection: Studies that assessed the association of quality- or quantity-based PE interventions with improvement in physical fitness and/or FMSs in youths (aged 3-18 years) were included. Data Extraction and Synthesis: Data were processed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Random-effects models were used to estimate the pooled effect size (Hedges g). Main Outcomes and Measures: Health-related physical fitness outcomes and FMSs. Results: Fifty-six trials composed of 48 185 youths (48% girls) were included in the meta-analysis. Quality-based PE interventions were associated with small increases in health-related physical fitness (cardiorespiratory fitness [Hedges g = 0.24; 95% CI, 0.16-0.32] and muscular strength [Hedges g = 0.19; 95% CI, 0.09-0.29]) and FMSs (Hedges g = 0.38; 95% CI, 0.27-0.49). Subgroup analyses found stronger associations for quality-based PE interventions on body mass index (Hedges g = -0.18; 95% CI, -0.26 to -0.09), body fat (Hedges g = -0.28; 95% CI, -0.37 to -0.18), cardiorespiratory fitness (Hedges g = 0.31; 95% CI, 0.23-0.39), and muscular strength (Hedges g = 0.29; 95% CI, 0.18-0.39). Quantity-based PE interventions were associated with small increases in only cardiorespiratory fitness (Hedges g = 0.42; 95% CI, 0.30-0.55), muscular strength (Hedges g = 0.20; 95% CI, 0.08-0.31), and speed agility (Hedges g = 0.29; 95% CI, 0.07-0.51). Conclusions and Relevance: The findings suggest that quality-based PE interventions are associated with small increases in both student health-related physical fitness components and FMSs regardless of frequency or duration of PE lessons. Because PE aims to improve more than health, high levels of active learning time may need to be balanced with opportunities for instruction, feedback, and reflection.

Exercise program and blood pressure in children: The moderating role of sedentary time.

OBJECTIVES: The aim of the present study was to test a before-school physical activity intervention (Active-Start intervention) on blood pressure in children and examine whether sedentary time moderates the effect of the intervention on blood pressure. DESIGN: Randomized controlled trial. METHODS: The Active-Start intervention comprising 170 children (8-10 years old) from three public schools with low socioeconomic status in Santiago (Chile). The exercise intervention was delivered daily, before starting the first school-class (8:00-8:30 a.m.), for 8 weeks. The intervention was mainly a program of cooperative physical games at moderate-vigorous intensity. Resting systolic and diastolic blood pressure was determined from the average of two measurements at baseline and at the end of intervention. Moderate-to-vigorous physical activity and sedentary time was assessed using a GENEActiv tri-axial accelerometer prior to the program intervention. RESULTS: The Active-Start intervention decreased blood pressure levels in children (p<0.01) but did not change relative to the control group. Johnson-Neyman analysis revealed a significant relationship between the effect of intervention on systolic blood pressure and mean arterial pressure when sedentary time was below, but not at or above, 657 and 659min per day (i.e., the effect of physical exercise disappears), respectively. CONCLUSIONS: The effect of physical activity on blood pressure could disappear in children with excessive sedentary time, which highlights the need to reduce total levels of sedentary time in the day-to-day life of young people in and out of schools.

Physical fitness components in relation to attention capacity in Latin American youth with overweight and obesity.

The aim of the study was twofold: (a) to examine the association between health-related physical fitness and attention capacity in Latin American children and adolescents with overweight and obesity and (b) to test whether body composition outcomes are moderators of this association. A cross-sectional design was used to study 201 overweight/obese participants (12.1 ± 2.1 years of age; 34.3% girls) from Chile (Active-Start study) and Colombia (HEPAFIT study). Body composition, muscular fitness, speed-agility, and cardiorespiratory fitness were evaluated using two similar test batteries (ALPHA and FUPRECOL). Attention capacity was measured by the d2 Test. Linear regression and moderation analyses were conducted. Linear regression analysis revealed an association between muscular fitness (ß = 0.245, P = .015), speed-agility (ß = -0.16, P = .027), cardiorespiratory fitness (ß = 0.331, P < .001) and overall fitness score (ß = 0.210; P = .004) and attention capacity (all analyses were controlled for age, sex, peak height velocity, maternal education, and study setting). Moderation analysis using the Johnson-Neyman technique revealed that the effect of the relationship between muscular fitness score and speed-agility and attention capacity was stronger as fat mass and fat mass index increased. In conclusion, physical fitness components are associated with higher attention capacity in youth with overweight/obesity, but body composition seems to moderate these relationships. Randomized controlled trials in this population would help to better understand whether improvements in different components of physical fitness lead to better attention capacity, especially in youth with excess adiposity.