Associations of obesity, movement behaviors, and socioeconomic status with fundamental movement skills in children: Results from the REACT project.

OBJECTIVE: To investigate the relationship of biological characteristics (age, sex, and obesity), movement behaviors (physical activity and sedentary time), and family socioeconomic status with fundamental movement skills (FMS) in primary school children. METHODS: This cross-sectional study sampled 1014 children (537 girls) aged 6 to 10 years from 25 primary schools in Matosinhos, north of Portugal. Five object control skills (dribbling, kicking, catching, throwing, and underarm rolling) were assessed with a categorical scale using the Meu Educativo® platform. Body Mass Index (BMI) was calculated and transformed into z-scores. Moderate-to-vigorous physical activity (MVPA) and sedentary time were monitored with accelerometry (ActiGraph wGT3X-BT) for seven consecutive days. Family socioeconomic status (SES) was obtained from the Portuguese social support system. Ordinal multilevel logistic regression was used to analyze the associations of weight status, MVPA, sedentary time and SES with FMS, adjusted for sex and age. RESULTS: Boys (odds ratio (OR) = 6.54; 95% CI: 5.13-8.36) and older children (OR = 2.04; 95% CI: 1.85-2.26) were more likely to achieve higher FMS scores. Children with obesity (OR = 0.60; 95% CI: 0.45-0.80), those less active (OR = 0.56; 95% CI: 0.42-0.75) and children with more sedentary time (OR = 0.86; 95%CI: 0.77-0.97) were less likely to score high on FMS. Family SES was not significantly associated with FMS scores. CONCLUSION: Primary school children's FMS are significantly related to biological and behavioral factors but not to family SES. These findings highlight the need for suitable strategies to enhance children's FMS proficiency, considering differences in these characteristics. Fostering adequate motor skill proficiency levels will assist in establishing a robust foundation for healthy lifestyles of all children.

Individual and school correlates of body mass index and cardiorespiratory fitness in primary school children from the REACT project: A multivariate multilevel analysis.

OBJECTIVE: This paper examines the relationship between body mass index (BMI) and cardiorespiratory fitness (CRF) using a multivariate multilevel approach and investigates the links between individual and school-related correlates with children's BMI and CRF. METHODS: This cross-sectional sample included 1014 children (6-10 years) from 25 Portuguese primary schools. BMI was calculated, and CRF was assessed with the PACER test. Fundamental movement skills (FMS) included five object control tasks. Moderate-to-vigorous physical activity (MVPA), sleep, and sedentary time were assessed with the ActiGraph wGT3X-BT accelerometer. Socioeconomic status (SES) and school variables were also obtained. A multivariate multilevel model was used, and alpha was set at 5%. RESULTS: BMI and CRF systematically increased with age. Most of the joint variance (94.4%) was explained at the child level, and BMI and CRF were correlated at this level (ρ = -.37). More active children demonstrated higher CRF levels and had lower BMI levels; sedentary and sleep time were not significantly associated with BMI or CRF. FMS were positively associated with CRF but were not significantly associated with BMI. Children at higher SES were more fit and had lower BMI than their peers of lower SES. Finally, school-level variables were not significantly related to BMI and CRF. CONCLUSION: BMI and CRF had a low but statistically significant negative correlation in this sample of children. Most of the variation in BMI and CRF was explained by child-level characteristics.

A multivariate multilevel approach to unravel the associations between individual and school factors on children's motor performance in the REACT project.

OBJECTIVE: The aim was to (1) estimate the relationship between physical fitness (PF) and object control fundamental movement skills (FMS), (2) identify child characteristics that relate with PF and FMS, and (3) examine associations between the school environment, PF, and FMS. METHODS: The sample included 1014 Portuguese children aged 6-10 years from the REACT project. PF was assessed via running speed, shuttle run, standing long jump, handgrip, and the PACER test. Object control FMS were assessed with stationary dribble, kick, catch, overhand throw, and underhand roll. Test performances were transformed into z-scores, and their sum was expressed as overall PF and FMS. Child-level variables included body mass index (BMI) z-scores, accelerometer-measured sedentary time and moderate-to-vigorous physical activity, and socioeconomic status (SES). School size, physical education classes, practice areas, and equipment were also assessed. RESULTS: Approximately, 90% of the variance in object control PF and FMS was at the child level, and 10% at the school level. The correlation between PF and object control FMS was .62, which declined to .43 with the inclusion of covariates. Older, more active, and higher SES children had higher object control PF and FMS, and boys outperformed girls. BMI was negatively associated with PF but not with object control FMS. Sedentary time and number of physical education classes were not significant predictors. Most school predictors did not jointly associate with PF and object control FMS. CONCLUSION: PF and object control FMS z-scores were moderately related. Not all child characteristics were associated with both PF and object control FMS, and their effect sizes were different. School characteristics only explained 10% of the total variation in PF and object control FMS.

Is there an association between proficiency in fundamental movement skills and mderate-to-vigorous physical activity in childhood on weekdays and weekends? The REACT project.

OBJECTIVE: The present study probes into the association between children's fundamental movement skills (FMS) and moderate-to-vigorous physical activity (MVPA) during weekdays and weekends. METHODS: This cross-sectional sample included 1014 children aged 6-10 years from the REACT project. Physical activity was assessed with accelerometry, and five FMS (stationary dribble, kick, catch, overhand throw, and underhand roll) were assessed with the digital platform Meu Educativo®. Three groups were formed based on the frequency of FMS that each child mastered: group 1 (wizard level in four or five FMS); group 2 (wizard level in two or three FMS); and group 3 (wizard level in at most one skill). Multilevel models were used to analyze the data treating children (level-1) nested within schools (level-2). RESULTS: Compared to group 1, groups 2 (-12.9 ± 2.3 min day-1) and 3 (-23.9 ± 2.4 min day-1) were less physically active during weekdays and weekends (group 2: -14.7 ± 2.7 min day-1 and group 3: -22.4 ± 2.9 min day-1), independent of age and sex. There was a decline in MVPA during the weekend. Further, on average, boys were more active than girls, and with increasing age, children were less active. CONCLUSION: On average, children with higher FMS levels are generally more physically active than their peers with lower FMS levels. Even though MVPA tends to decline on weekends, FMS proficiency is a significant factor in maintaining 60 min of MVPA on weekends.

Validity and reliability of Meu Educativo®: A new tool to assess fundamental movement skills in school-aged children.

OBJECTIVES: There is evidence showing that children's proficiency in fundamental movement skills (FMS) is positively related to weight status, physical activity, fitness levels, cognitive development, as well as academic performance. Yet, the feasibility of FMS assessment is challenging, especially with relatively large samples of children. This article presents a new tool named Meu Educativo® to assess children's FMS levels, including its validity and reliability. METHODS: We relied on the validity evidence approach based on test content to develop the FMS assessment checklist and the rating system with a team of experts. In this article, we used five FMS (stationary dribbling, kick, overhand throw, catch the ball, and underhand roll). Further, we conducted a series of reliability studies and used percent agreement and Cohen's kappa (κ) as statistics. RESULTS: Experts agreed highly on the checklist's components in the five FMS. Inter-rater reliability ranged from 0.63 for stationary dribbling to 0.93 for overhand throw, and the intra-rater reliability ranged from 0.46 to 0.94. CONCLUSION: Based on the first results, Meu Educativo® was not only easy to use, but was also a reliable tool for FMS assessments. Notwithstanding the need for future studies, Meu Educativo® is a new tool that can be used by teachers, coaches, and motor development specialists dealing with school-aged children and researchers working with large samples.

Background, rationale, and methodological overview of the REACT project-return-to-action on growth, motor development, and health after the COVID-19 pandemic in primary school children.

OBJECTIVES: The REACT project was designed around two main aims: (1) to assess children's growth and motor development after the COVID-19 pandemic and (2) to follow their fundamental movement skills' developmental trajectories over 18 months using a novel technological device (Meu Educativo®) in their physical education classes. In this introductory article, the first of the Journal's special issue dedicated to REACT, our goal was to present the project rationale, its methodology, training and certification of the team, statistical approach, quality control, governance, and study management. METHODS: We sampled 1000 children (6-10 years of age) from 25 of the 32 primary schools in Matosinhos, northern Portugal. The protocol included a set of variables clustered around the child (growth, physical fitness, fundamental movement skills, and health behaviors), family (demographics, socioeconomic status, parental support for sports participation and physical activity), school (policies and practices for health behaviors, infrastructure for physical education and sports practices), and neighborhood and home environments (safety, sidewalks, sports facilities, as well as children electronic devices and play equipment at home). A set of standard protocols were implemented in REACT together with a rigorous system of training and certification of all members of the research team. This was complemented with a pilot study to assess, in loco, the quality of data acquisition, data entry, and control. DISCUSSION: Results from REACT will provide school administrators and teachers with novel and far-reaching information related to children's growth and motor development as well as health behaviors after the COVID-19 pandemic. It will also provide city-hall education officials with insight regarding children's physical fitness, fundamental movement skills, and sports practices that will be of great importance in devising novel intervention programs to increase health-enhancing physical activity, and combat sedentariness and obesity. Finally, it will offer parents a wealth of information regarding their children's growth, motor development, and health.

Statistical analysis of the longitudinal fundamental movement skills data in the REACT project using the multilevel ordinal logistic model.

OBJECTIVES: The REACT project was designed around two main aims: (1) to assess children's growth and motor development after the COVID-19 pandemic and (2) to follow their fundamental movement skills' developmental trajectories over 18 months using a novel technological device (Meu Educativo®) in their physical education classes. In this article, our goal is to describe statistical analysis of the longitudinal ordinal motor development data that was obtained from these children using the multilevel ordinal logistic model. METHODS: Longitudinal ordinal data are often collected in studies on motor development. For example, children or adolescents might be rated as having poor, good, or excellent performance levels in fundamental movement skills, and such ratings may be obtained yearly over time to assess changes in fundamental movement skills levels of performance. However, such longitudinal ordinal data are often analyzed using either methods for continuous outcomes, or by dichotomizing the ordinal outcome and using methods for binary data. These approaches are not optimal, and so we describe in detail the use of the multilevel ordinal logistic model for analysis of such data from the REACT project. Our intent is to provide an accessible description and application of this model for analysis of ordinal motor development data. DISCUSSION: Our analyses show both the between-subjects and within-subjects effects of age on motor development outcomes across three timepoints. The between-subjects effect of age indicate that children that are older have higher motor development ratings, relative to thoese that are younger, whereas the within-subject effect of age indicates higher motor development ratings as a child ages. It is the latter effect that is particularly of interest in longitudinal studies of motor development, and an important advantage of using the multilevel ordinal logistic model relative to more traditional methods.

Sleep and fundamental movement skills in primary schoolchildren: The REACT project.

OBJECTIVE: Whether sleep is related to fundamental movement skills (FMS) in the pediatric population is largely unknown. The objective of this study was to examine the association between sleep characteristics (duration, efficiency, regularity) and FMS proficiency levels in school-aged children. METHODS: This cross-sectional study included 996 children (mean age: 8.3 ± 1.2 years) from 25 of the 32 primary schools in Matosinhos, northern Portugal. Data collection occurred between January and June 2022. Sleep was assessed using an ActiGraph wGT3X-BT accelerometer worn on the wrist for 7 consecutive days. FMS proficiency levels were assessed in the schools with a new digital platform (Meu Educativo®) that evaluated five object control skills (dribble, kick, catch, throw, and underhand roll), with a total score ranging between 5 and 15. Multilevel ordinal logistic regression was used to test the associations between sleep characteristics and FMS proficiency levels. Covariates included age, sex, body mass index z-score, socioeconomic status, and moderate-to-vigorous physical activity. RESULTS: The results showed that sleep characteristics (duration, efficiency, and regularity) were not related to FMS proficiency. Being a boy, older age, and higher moderate-to-vigorous physical activity levels were all significantly associated with better FMS proficiency levels. There were no significant sex-by-age interactions. CONCLUSION: Sleep was not found to be related to FMS performance in children. This finding suggests that sleep is not a good correlate of FMS proficiency levels in school-aged children, and attention should be dedicated to other more important factors such as skill-learning-specific physical activity.

Sibling Resemblances in Physical Fitness in Three Distinct Regions in Peru: The Peruvian Sibling Study on Growth and Health.

We estimated sibling resemblance in health-related physical fitness (PF) and examined how individual characteristics and shared natural environment accounted for sibling similarities. The sample comprised 656 sibling pairs and 102 triplets (6-15 years of age), from three geographical areas of Peru. PF components included morphological (waist circumference, sum of skinfolds), muscular (handgrip strength, standing long jump), and motor (shuttle-run). Body mass index (BMI) and somatic maturation were also assessed. In general, sibling intraclass correlations differed significantly across sib-ship types for waist circumference and handgrip strength but were the same for sum of skinfolds, standing long jump, and shuttle-run. Further, in general, both individual characteristics and geographical area of residence significantly influenced the magnitude of sibling resemblance as well as the mean levels of PF. In conclusion, individual characteristics and shared natural environment jointly influenced the expression of PF in Peruvian siblings, revealing the importance of these features when designing individualized programs promoting fitness.

Physical fitness spurts in pre-adolescent boys and girls: Timing, intensity and sequencing.

We aim to (1) estimate age of attainment of the peak mid-growth spurt in stature (age-at-peak MGS) in pre-adolescent boys and girls; (2) identify the timing, intensity, and sequences of physical fitness (PF) spurts aligned by the age-at-peak MGS; and (3) identify any sex differences in PF spurts aligned by age-at-peak MGS. The sample included 180 Portuguese children (90 girls) aged 6 to 10 years at study entry who were followed annually for 4 years. Height, health-, and performance-related PF were assessed. Age-at-peak MGS and PF spurts were estimated using a non-smooth mathematical procedure. Boys' and girls' age-at-peak MGS occurred at 7.8 ± 0.47 years and 8.0 ± 0.72 years, respectively. PF spurts' timing aligned by age-at-peak MGS were as follows: (1) before age-at-peak MGS: boys - static strength, aerobic capacity, explosive leg strength, and flexibility; girls - speed, agility, aerobic capacity, and upper body strength; (2) coincident with age-at-peak MGS: girls - explosive leg strength and flexibility; (3) after age-at-peak MGS: boys - abdominal strength, upper body strength, agility, and speed; girls - abdominal strength and static strength. Boys and girls attained their MGS at relatively similar ages. However, the timing and sequences of PF spurts, aligned on age-at-MGS, were different between boys and girls.

Physical fitness spurts in childhood: A study in boys.

This study aimed to (1) estimate age-at-mid-growth spurt (age-at-MGS) in Portuguese boys from two different regions-the Azores islands and Viana do Castelo, and (2) identify spurts in a variety of physical fitness (PF) components aligned by age-at-MGS in the two samples. A total of 176 (Azores, n = 91; Viana do Castelo, n = 85) boys aged 6 years old were followed annually to 10 years of age. Age-at-MGS and spurts in PF components (speed, explosive muscular strength, abdominal muscular strength, agility, and flexibility) were identified for each sample. The timing and intensities of the spurts were estimated using a non-smooth mathematical procedure. In Azorean boys, age-at-MGS occurred at 7.8 years (6.99 cm y-1 ), whereas in Viana do Castelo it occurred at 7.9 years (6.20 cm y-1 ). Spurt in speed was attained 12 months after the MGS in both samples (0.53 and 0.35 cm y-1 in Azores and Viana do Castelo, respectively), whereas spurts in explosive muscular strength and flexibility occurred 12 months before the MGS and at the MGS (Azores: 21.59 and 5.52 cm y-1 and Viana do Castelo: 14.12 and 2.5 cm y-1 , respectively). Agility and abdominal muscular strength peaked between 0 and 12 months after the MGS (Viana do Castelo: 0.37 m s-1  y-1 and 6.71 reps y-1 and Azores: 0.28 m s-1  y-1 and 19.36 reps y-1 , respectively). Results indicate that developmental spurts in explosive strength and flexibility occur before, or are coincident with, the mid-growth spurt in height, whereas spurts in speed, agility, and abdominal muscular strength occur after, or coincident with, the mid-growth spurt in height.

Physical Activity Measured by Accelerometry in Mozambican Older Adult Women Attending a Regular Exercise Program.

Time spent in different Physical Activity (PA) Intensities of 72 Mozambican older adult women (67 ± 7 years old) was assessed by means of triaxial accelerometers for 7 consecutive days, and participants were stratified based on their body mass index, as being normal weight (NW, n = 23); overweight (n = 16); or obese (OB, n = 33). Overall, most daily time was spent in sedentary activities (614 ± 111 min or 69.1%) and light PA (181 ± 56 min or 20.2%). On average, moderate to vigorous PA (MVPA) was performed during 10.6% of the day (93 ± 44 min). Time spent in MVPA was significantly higher in the NW compared to OB category (112.8 ± 51.5 vs. 81.0 ± 36.3; p = .021). The overweight group did not differ in time spent in MVPA when compared to NW and OB group. Overall, 75% of the participants spent more than 60 min a day in MVPA (NW: 83%; overweight: 81%; OB: 67%). Pearson's correlation between body mass index and total MVPA controlling for age was -.39 (p < .001). It was concluded that Mozambican older adult women living in urban and rural areas of Maputo province engaged in relatively high Physical Activity Intensities compared with individuals of similar ages in high-income countries, regardless of their nutritional status.

A multivariate multilevel analysis of youth motor competence. The Peruvian Health and Optimist Growth Study.

We use a multivariate multilevel model to study the links between physical fitness (PF) and gross motor coordination (GMC) and investigate the influence of predictors affecting their levels across age. We sampled 7918 Peruvians, aged 6-15 years, from sea-level, Amazon region and high-altitude. Composite markers of GMC and PF were derived (GMCz and PFz , respectively). BMI, biological maturation, and stunting were assessed. School characteristics were obtained via an objective audit. School contexts explained 35% of the associations between PFz and GMCz , whereas children's characteristics explained 65% of the total variation. On average, with increasing age, there was a greater increase in GMCz (ß = 0.79 ± 0.04, P < .001) than in PFz (ß = 0.15 ± 0.03, P < .001); boys outperformed girls (PFz , ß = 3.25 ± 0.08, P < .001; GMCz , ß = 1.58 ± 0.09, P < .001); those with lower BMI and ahead in their maturation had higher PFz (ß = -0.13 ± 0.01, P < .001; ß = 1.09 ± 0.05, P < .001, respectively) and GMCz (ß = -0.18 ± 0.01, P < .001; ß = 0.39 ± 0.06, P < .001, respectively) levels. Stunting was negatively related to PFz (ß = -0.30 ± 0.07; P < .001) and GMCz (ß = -0.30 ± 0.08, P < .001) and high-altitude Peruvians had significantly lower GMCz (ß = -0.93 ± 0.33, P < .001), and those living in the Amazon region had significantly higher PFz (ß = 1.21 ± 0.58, P < .001) compared to those living at sea level. A higher number of students was negatively related to PFz (ß = -0.016 ± 0.006, P < .001) and positively with GMCz (ß = 0.005 ± 0.003, P < .001); the duration of physical education classes was positively associated with PFz (ß = 0.70 ± 0.32, P < .001) and GMCz (ß = 0.46 ± 0.15, P < .001); and the existence of policies for physical activity was only negatively associated with GMCz (ß = -1.17 ± 0.34, P < .001). In conclusion, PFz and GMCz were positively correlated and child- and school-level traits predicted their levels.

Patterns of physical performance spurts during adolescence: a cross-cultural study of Canadian, Brazilian and Portuguese boys.

BACKGROUND: Data relating physical performance to the timing of the adolescent growth spurt are limited. Aim: This study identifies: (i) age-at-peak height velocity (APHV), (ii) physical performance spurt patterns aligned to APHV; and (iii) cross-cultural and time patterns in Canadian, Brazilian and Portuguese boys. Subjects and methods: A total of 512 boys (131 Canadian, 250 Portuguese and 131 Brazilian), 8-17 years of age were followed serially using longitudinal data. APHV was identified and five physical performance measures velocities [trunk extension (TE), trunk flexion (TF), standing long jump (SLJ), curl-ups (CU) and handgrip strength (HG)] were aligned at 6-month intervals, 4 years around the attainment of PHV. Velocities were estimated using a non-smooth mathematical procedure. Results: APHV was 13.9 ± 1.0, 13.4 ± 1.6 and 13.0 ± 0.8 years for Canadian, Brazilian and Portuguese boys, respectively. Maximal velocity in SLJ was attained between 12 and 6 months prior to PHV. For HG, peaks were attained 12-24 months after PHV. Maximal velocity in TE occurred between 12 and 0 months prior to PHV, while CU peaked between PHV and 6 months after PHV. Conclusion: Patterns of spurts in physical performance have remained relatively the same and do not appear to be influenced by cross-cultural differences.

Are there gross motor coordination spurts during mid-childhood?

OBJECTIVES: The aims of this study were (1) to identify the timing of the mid-growth spurt (MGS) in stature in children and (2) to identify gross motor coordination (GMC) spurts when aligned by the age of attainment of the MGS (aMGS). METHODS: Stature, weight, and GMC were measured in 245 Portuguese children followed annually from 6 to 10 years. GMC was assessed and to estimate children's MGS in stature as well as GMC spurts in each of the four tests aligned by aMGS, we used a nonsmoothed polynomial methodology. RESULTS: In boys, the aMGS was attained at 7.8 years, whereas in girls it was 8.0 years. In boys, the peak MGS was 6.2 cm∙yr-1 and in girls it was 6.4 cm∙yr-1 . In boys, the peak for walking backwards (WB) occurred 18 months before aMGS (14.9-points∙yr-1 ), jumping sideways (JS) was 12 months after aMGS (13.5-points∙yr-1 ), hopping on one leg (HO) was 18 months before aMGS (11.7-points∙yr-1 ), and shifting platform (SP) was 12 months before aMGS (6.8-points∙yr-1 ). In girls, WB spurts occurred 12 months after aMGS (13.3-points∙yr-1 ), JS was 12 months before aMGS (10.5-points∙yr-1 ), HO was coincident with aMGS (10.4-points∙yr-1 ), and SP was 18 as well as 12 months before aMGS (7.2-points∙yr-1 ). No differences were observed in the mean peak spurts between sexes in the GMC tests. CONCLUSIONS: Boys and girls reached their MGS in stature at about the same chronological age. Spurts in GMC did not express themselves in the same biological timing relative to aMGS in stature, and there are sex differences.

Modelling the dynamics of children's gross motor coordination.

This study modelled children's gross motor coordination, investigated sex-differences and identified the effects of fixed and dynamic correlates on motor coordination development. A total of 344 Portuguese children (170 girls), from 6 age cohorts (5 to 9 years of age), were followed consecutively for three years (age range 5 to 11 years) using a mixed-longitudinal cohort design. Birth weight, hand dominance and socioeconomic status (SES) were identified. Gross motor coordination, body mass index, physical fitness (PF) and physical activity (PA) were assessed annually. A sequence of multilevel hierarchical linear models were developed. Model 1 found that age, age2, sex, sex-by-age and sex-by-age2 were significant predictors (p < 0.05) of gross motor coordination. Boys outperformed girls from 6 years of age onwards. Model 2 found a cohort effect (p < 0.05). Model 3 found that right handers were more coordinated (p < 0.05). When the confounders of body mass index, PF and PA were added to the model (Model 4) it was found that boys and girls had parallel trajectories in their gross motor coordination development. In conclusion children with increasing body mass index were less coordinated, while those who were stronger and more agile had steeper trajectories of gross motor coordination with age.

Tracking of gross motor coordination in Portuguese children.

The purpose of this study was to investigate the tracking of gross motor coordination (GMC) and to profile children at 6 years of age who consistently showed higher stability patterns in different levels of GMC. The participants were 245 children (123 boys and 122 girls) who were assessed longitudinally from 6 to 9 years of age. GMC was assessed using the Korperkoordinationtest fur Kinder (KTK) test battery. Anthropometry, physical activity, and health- and performance-related physical fitness were also measured. Cohen's kappa (κ) was used to estimate tracking. Tracking was poor for all GMC tests (0.17 ≤ κ ≤ 0.38) and moderate for the GMC motor quotient (MQ) in both boys and girls (0.44 ≤ κ ≤ 0.45). Instability at the extremes was low in GMC tests and negligible for MQ. Children who consistently showed high GMC levels during the 4 years of follow-up were lighter, had lower body mass index and subcutaneous fat, and showed higher scores in physical fitness tests at 6 years of age than those who consistently had low GMC levels. In conclusion, GMC showed low-to-moderate tracking over time in childhood. However, children who consistently demonstrated high GMC levels over time had healthier profiles at 6 years of age.

A mixed-longitudinal study of children's growth, motor development and cognition. Design, methods and baseline results on sex-differences.

BACKGROUND: There is a renewed interest in longitudinal studies which link children's growth, motor and cognition development. This is important for both educational outcomes and identification of children who are at risk. AIM: To identify cross-sectional sex-differences. SUBJECTS AND METHODS: In total, 1166 Portuguese children, aged 4-11 years, were recruited into the Growth, Motor Development and Cognition Study (GMDC-Vouzela study). Measures included: anthropometry, gestational development, motor coordination, cognitive performance, laterality, physical fitness, metabolic syndrome risk, lifestyle characteristics and environmental exposures. Analysis of covariance was used to compare outcomes between boys and girls, adjusting for chronological age. RESULTS: Most variables did not show significant differences between the sexes (p > 0.05). However, girls had more body fat mass than boys (p < 0.05) and boys were significantly heavier at birth (p < 0.05); furthermore, boys outperformed girls in a hopping high coordination test (p < 0.001) and were more physically fit (p < 0.05). CONCLUSIONS: Baseline results from the GMDC-Vouzela study indicate the dynamic relationships between children's biological and environmental characteristics. They also highlight lifestyle traits that will most likely effect subsequent growth, motor and cognitive development.

Familial resemblance in gross motor coordination. The Peruvian Sibling Study on Growth and Health.

BACKGROUND: The development of gross motor coordination (GMC) is governed by biological and environmental factors whose effect sizes are still unclear. AIM: To investigate sibling resemblance in GMC, as well as biological and environmental correlates of GMC among Peruvian children. MATERIALS AND METHODS: The sample comprised 1256 biological siblings (6-15 years old), from three geographical areas of Peru. GMC was assessed using the Korperkoordinationtest für Kinder (KTK) test battery. Anthropometry, biological maturation and physical fitness (PF) were also measured. Multilevel modelling was performed using Stata 14 software. RESULTS: In general, sister-sister pairs (SS) showed the highest resemblance in GMC (ρ = 0.24) compared to brother-sister (BS) (ρ = 0.10) and brother-brother (BB) pairs (ρ = 0.07). On average, BB pairs had higher GMC than SS pairs and older siblings had higher GMC than younger siblings. Further, those with lower body mass index (BMI) and higher PF had higher GMC. There was also a significant interaction between age and PF with GMC. Siblings from the rainforest region demonstrated higher GMC than those from sea level and high-altitude siblings demonstrated lower GMC than their sea-level peers. CONCLUSION: These results demonstrate statistically significant sibling resemblance in GMC. Age, BMI, PF and geographical area were significant correlates of GMC.

A multi-level analysis of individual- and school-level correlates of physical fitness in children.

BACKGROUND: Children's physical fitness is potentially influenced by biological, behavioural and environmental factors. AIM: To investigate the importance of individual-level and school-level characteristics in explaining variation in children's physical fitness. SUBJECTS AND METHODS: The sample comprised 354 Portuguese children, aged 5-10 years. Physical fitness [(handgrip (HG) strength, standing long jump (SLJ), shuttle-run (SR), total physical fitness score (PFz)], gross motor coordination (GMC) and body mass index (BMI) were assessed. Moderate-to-vigorous physical activity (MVPA) was objectively monitored; birth weight and socio-economic status (SES) were obtained by questionnaire. School contexts were assessed via an objective audit. Multilevel models using the Bayesian approach were used. RESULTS: Age was positively associated with HG, SLJ and PFz (p < 0.05); BMI was positively associated with HG (p < 0.05) and GMC with all physical fitness components (p < 0.05); MVPA was only associated with PFz (p < 0.05); children with level A SES outperformed those with level C SES in HG (p < 0.05), but those with level B SES outperformed their level A SES peers in SR (p < 0.05). Within the school context, no equipment for physical education was negatively associated with HG (p < 0.05). CONCLUSION: In the primary school years, individual-level characteristics were more important than the school context in explaining variations in physical fitness.