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Menarche is a significant pubertal event influencing girls' participation in physical activity. As menarche is a sensitive matter, a non-invasive substitute is needed to help classify girls' maturity status and provide physical literacy to them in this regard. The objective of this exploratory study was to investigate the classification agreement between self-reported age of menarche and calculated maturity offset in adolescent girls from South Africa by making use of various statistical methods. Fifty-eight girls, n = 13 pre- and n = 45 post-menarche (Status Quo method) aged 13.51 ± 3.51 years at baseline, were analyzed (2010-2012). Independent t-testing, cross-tabulation, Roc Curve statistics and logistic regression were used to analyze the classification agreement between markers. All four statistical methods revealed the potential to categorize different maturity groups through the maturity offset equation, although the accuracy declined with increased age. A realized power of 0.92 was found for the group in the first year of the study, with a gradual and significant decline over time. Cross-tabs showed a significant moderate predictive effectiveness (Chi-square = 0.042) during T1, closer to PHV (13.51 years) although also declining significantly with increased age (T2, 14.51 years) beyond PHV (Chi-square = 0.459). Although positive results were found, caution must be used when using maturity offset equations in different homogenic populations due to their unique growth characteristics.

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BACKGROUND:  Childhood is an important transitional period for the development of healthy physical activity (PA) behaviours, so it is important to understand its impact on a healthy lifestyle. AIM:  This study aimed to determine the influences of sex, socioeconomic status (SES) and body composition (BC) on the relationships between PA, motor skills, motor- and health-related physical fitness in 5-8-year-olds. SETTING:  Participants were a subsample consisting of 299 children (150 boys, 149 girls, mean age 6.83 ± 0.96 years) from the Exercise, Arterial Modulation and Nutrition in Youth South Africa study (ExAMIN Youth SA). METHODS:  Anthropometric measures, health-related physical fitness (HRPF), motor-related physical fitness (MRPF), objectively measured PA and demographic information were determined. RESULTS:  Only 66% achieved the recommended 60 min of daily moderate vigorous physical activity (MVPA) with 19% classified as having unhealthy body composition (11% overweight, 8% obese). Fat-free mass and SES revealed small-to-moderate influences on the relationship between MVPA, standing broad jump (SBJ; r = 0.32), predicted VO2max (r = 0.28) and beep levels (r = 0.22). For MRPF, the quality of running (r = 0.12) and balancing were associated with MVPA. Adjusting for sex, BC and SES in the relationship between PA with HRPF and MRPF, reductions in most correlations were observed. CONCLUSION:  Moderate vigorous physical activity levels were positively associated with HRPF, MRPF and some motor skills in 5-8-year-olds. Socioeconomic status (lower parental income, employment and education negatively influenced the association between MVPA and fitness [beeps, SBJ, O2max]).Contribution: This study provides knowledge with regard to the use of accelerometer for baseline data for PA, MRPF, HRPF as well as motor skills in South African children.

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Pediatric obesity has become a growing global epidemic which has negative health consequences, including for South African children. This study aimed to determine the immediate and sustainable influences of a 9-week movement program on the body composition of 7 to 8-year-old school children in a rural area of South Africa. A two group, pre-test, post-test and re-test after six months experimental design was used to compare anthropometric measurements of the intervention group (IG) and control group (CG). Ninety-three schoolchildren (IG = 57; CG = 36) participated in the study. A 9-week movement program was followed twice a week for 30 min during school hours with an emphasis on improving BMI. Hierarchical Linear Modelling (HLM) was used to analyze the data with time, sex and group as predictors. Effect sizes was computed based on the Cohen's d to assess the practical significance of findings. The intervention positively changed the waist circumference. The subscapular skinfold and BMI showed statistical and practically significant sustainable changes because of the intervention, although gender influenced these effects. School based movement interventions, focusing on improving fundamental movement skills (FMS), have the potential to contribute to a healthier BMI, skinfold thickness and circumferences among young children.

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Adequate development of Fundamental Motor Skills (FMS) at a young age benefit holistic development and positive health outcomes. This study determined age and sex developmental differences in the state and the relationships between process and product assessments of four fundamental-motor skills (FMS) in five to eight-year-olds. An availability sample of 636 children; 291 boys, 345 girls, mean age of 6.8 ± 0.97 years in the North West Province of South Africa participated in the study. Spearman rank order correlations analyzed relationships between assessments, while sex and age differences were examined using independent t-testing and one-way ANOVA. Age showed significant developmental trajectories in all FMS. Older children were found to be more at risk for not learning FMS to mastery, while unique developmental patterns were also established compared to international trends. Strong to moderate significant practical associations (p < 0.05) emerged between process and product assessments in catching (r = 0.79), jumping (r = 0.40) running (r = −0.33) and kicking (r = 0.20), while also confirming that the strength of the associations varies depending upon the skill type. Associations strengthened with increasing age, were higher in girls in all FMS, while associations between behavioral criteria in all FMS also differed between FMS and sexes. These strong associations, need to be taken into consideration during the development of FMS towards obtaining full mastery.

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ABSTRACT: Badenhorst, J, Pienaar, AE, and Gerber, BP. The effect of the growth spurt on training of strength and power during mid-adolescence in boys. J Strength Cond Res 35(8): 2193-2204, 2021-This study determined if the growth spurt will influence the training of strength and power in boys (N = 86) of differing maturity levels. Based on a 2-group, pretest posttest design within a 2 school-year follow-up period, including 4 time point measurements, an experimental group (EG), who participated in different school sports were subjected to an additional 6 months, strength and power training program, twice a week for 45 minutes over 2 consecutive years (n = 47, 13.67 ± 0.26 years). They were compared with boys (n = 39, 13.68 ± 0.16 years) serving as a control group (CG) for normal growth who did not compete in any sports or training programs. Both EG and CG were subdivided into 3 maturity groups, late developers (LD), early developers, and typical developers (TD) based on a linear growth rate. Assessments were performed every 6 months for changes in height, body mass, strength, and power. Differences within and between the EG, CG, and maturity groups were analyzed using repeated measures analysis of variance and hierarchical linear modeling, whereas significance of practical differences were determined by effect sizes (d). Early developers presented with training effects, whereas TD and LD showed conditioning and adaptation responses to training. Customized training to leverage the different maturation levels in a way to optimize strength and power advancement is important for the preparation of boys for sports participation during mid-adolescence because it can positively affect adaptation and responsiveness to training in boys of different maturity levels.

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Puberty and the onset of menarche influences the motor performance of girls. However, the magnitude of these influences during varying maturity status, is not clear. This longitudinal study over two years aimed to investigate differences in motor fitness between early and late developing girls based on pre- and post-menarche status. A convenience sample (n = 58) of girls aged 13.51 ± 3.51, divided by means of the Status Quo method into pre (n = 13) and post-menarche (n = 45) groups, was used. Motor fitness was tested once annually by standardized protocols. Basic statistics, independent t-testing and a repeated measures ANOVA with a post hoc Bonferonni correction were used (p < 0.05 = statistical significance). Effect sizes were determined by Cohen's d-values. Only explosive upper body strength differed significantly between groups during baseline, favoring post-menarche girls. Initially, post-menarche girls showed advantages in hand-eye coordination and speed (p > 0.05) with pre-menarche girls performing better in agility and explosive leg strength (p > 0.05). At 15.51 years, no significant, between-group differences were found. Pre-menarche girls surpassed post-menarche girls in hand-eye coordination and 0-40 m speed and post-menarche girls displayed higher explosive leg and upper body strength scores (p > 0.05). Our data show that the potential to excel in sport based on motor capabilities can only be accurately estimated 1-2 years after reaching menarche.

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The level of competency in object control skills (OCSs) during early childhood is considered to be a possible determinant of the successful generalization of these skills during later childhood. This study aimed to determine if an association exists between competency in object control skills during early childhood (6-9 years) and the application of these skills during later childhood (12 years). The NW-CHILD longitudinal study (2010-2016), included a baseline and two time-point follow-up measures in grades 1, 4, and 7 of South African children. A total of 374 participants (boys = 178, 47.59% and girls = 196, 52.41%) completed testing at all three time-points and were analyzed. The Test of Gross Motor Development, Second Edition, and the Canadian Agility and Movement Skill Assessment were used to determine associations between object control skill competency during early and later childhood by using descriptive statistics, Spearman rank order correlations, and stepwise regression analysis. The level of object control skill competency at 6 and 9 years, significantly influences the application of these skills at 12 years. A high overall and significant contribution of OCS (4.6%, p < 0.01) to the variance in the skills and time scores at 12 years; p < 0.05 were found. Competence in object control skills at an early age can provide a baseline from where opportunities for progression or transfer of skills can result in more advanced skillful executions which consequently can be considered to be a cornerstone of improved future physical activity and healthier lifestyles.

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BACKGROUND: Overweight and obesity contribute to multiple health risks in children, while also impacting negatively on educational performance. Physical fitness can impact outcomes beyond health related measures therefore it can play a mediating role in combating the negative effects of being overweight. METHODS: One hundred and seventy-two primary school girls aged 6-13 years old from the North West Province of South Africa formed part of this random stratified longitudinal research design in which three follow-up measurements took place over seven years. Body Mass Index was used to compile obesity profiles, while the progressive aerobic cardiovascular endurance run (PACER) was used to determine cardiovascular fitness. Academic school achievements for grades 1, grade 4 and grade 7, as well as national and provincial values were correlated with academic performance. Data were analyzed by a repeated measure over time ANOVA as well using a latent growth curve model from the structural equation modelling framework (SEM). RESULTS: No differences (P>0.05) were found in the academic performance of obese and normal weight girls, although obese girls showed poorer physical fitness values (P<0.05). The SEM model was a good fit for all requirements (RMSEA, 0.60; CMIN DF, 2.837; CFI, 0.966). VO2max had a standardized indirect mediation effect (-132) while body composition showing a standardized direct effect (0.183) with academic achievement. Physical fitness showed a mediation effect with regard to obesity and academic achievement in grade 7 girls. CONCLUSIONS: Although the academic performance of obese girls did not show impairment before the age of 12 years, physical fitness had a reversible effect on relationships between obesity and academic achievement. This substantial influence of physical fitness should be used strategically in preventive intervention programs necessary to enhance cognitive functioning, academic performance and brain health among overweight children.

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BACKGROUND: Early childhood is characterised by an immense spurt of growing and learning where under-nutrition can have adverse effects on the neuro-developmental health and school performance of children. A full understanding of the relationship between school performance and motor functioning skills and malnourishment in school beginners is still lacking. AIM: To determine the association between indices of under-nutrition and how it relates to school performance and motor functioning skills of first-grade learners. SETTING: North West province (NWP) of South Africa (SA). METHOD: The baseline data of the stratified, randomised North-West Child Health Integrated with Learning and Development (NW-CHILD) longitudinal study were used. Grade 1 learners (N = 816, 420 boys, 396 girls, mean age 6.78+ years) from four school districts in the NWP of SA took part in the study. Indices of under-nutrition were determined by Z-scores (-2 standard deviation [s.d.]) for stunting (height-for-age [HAZ]) and wasting and underweight (Z-score for body mass index) using the 2007 World Health Organization reference sample. The Bruininks-Oseretsky Test of Motor Proficiency Short Form and the Visual Motor Integration fourth edition were used to assess different aspects of motor functioning, while school performance in mathematics, reading and writing was assessed by teachers according to the National South African standards of assessments. RESULTS: Both HAZ and Z-score for weight-for-age correlated significantly with school performance and motor functioning skills (r > 2.0, p < 0.05), while visual perception was moderately associated (r < 0.30) with mathematics in HAZ and Z-score for weight-for-height (WHZ) children. Motor functioning of HAZ and WHZ children was significantly poorer (p < 0.05) compared to typical children, while underweight was not associated with any outcome variables. CONCLUSION: Moderate forms of stunting and wasting influence school performance and motor functioning of school beginners negatively, while an association between visual perceptual abilities and inferior mathematics, reading and writing suggests a close link with inferior cognitive information processing in stunted and wasted children. These barriers should be addressed as poor scholastic success in Grade 1 may influence future school performance and the subsequent well-being of children.

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Background: Early childhood is characterised by an immense spurt of growing and learning where under-nutrition can have adverse effects on the neuro-developmental health and school performance of children. A full understanding of the relationship between school performance and motor functioning skills and malnourishment in school beginners is still lacking. Aim: To determine the association between indices of under-nutrition and how it relates to school performance and motor functioning skills of first-grade learners. Setting: North West province (NWP) of South Africa (SA). Method: The baseline data of the stratified, randomised North-West Child Health Integrated with Learning and Development (NW-CHILD) longitudinal study were used. Grade 1 learners (N= 816, 420 boys, 396 girls, mean age 6.78+ years) from four school districts in the NWP of SA took part in the study. Indices of under-nutrition were determined by Z-scores (−2standard deviation [s.d.]) for stunting (height-for-age [HAZ]) and wasting and underweight (Z-score for body mass index) using the 2007 World Health Organization reference sample. The Bruininks­Oseretsky Test of Motor Proficiency Short Form and the Visual Motor Integration fourth edition were used to assess different aspects of motor functioning, while school performance in mathematics, reading and writing was assessed by teachers according to the National South African standards of assessments. Results: Both HAZ and Z-score for weight-for-age correlated significantly with school performance and motor functioning skills (r> 2.0, p< 0.05), while visual perception was moderately associated (r< 0.30) with mathematics in HAZ and Z-score for weight-for-height (WHZ) children. Motor functioning of HAZ and WHZ children was significantly poorer (p<0.05) compared to typical children, while underweight was not associated with any outcome variables.Conclusion: Moderate forms of stunting and wasting influence school performance and motor functioning of school beginners negatively, while an association between visual perceptual abilities and inferior mathematics, reading and writing suggests a close link with inferior cognitive information processing in stunted and wasted children. These barriers should be addressed as poor scholastic success in Grade 1 may influence future school performance and the subsequent well-being of children

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Visual perception plays an important and integrating role in the development of cognitive abilities and perceptual-motor skills. Visual perception comprises different independent constructs that may function in an integrative manner. This study aimed to determine whether (and the extent to which) various visual-perceptual constructs influence the academic achievement of 12-year-old school children. In a cross-sectional analysis, we extracted only 2016 data from 581 learners (mean age = 12.92 years, SD = 0.42) who were participants in the North-West Child Health, Integrated with Learning and Development longitudinal study (2010-2016). We used the Test of Visual Perceptual Skills, Third Edition, the North-West Provincial Assessment and mid-year school examination reports to determine visual perceptual abilities and academic achievement of this participant group. We calculated correlations between visual perceptual constructs and academic performance using Spearman rank order correlations and separately analyzed the influence of gender and socioeconomic status with independent T tests. Different visual perceptual constructs did have significant influences on specific areas of academic learning and on academic achievement generally ( r = .26 to r = .41). Spatial relationships showed slightly greater correlations with academic achievement ( r = .15 to r = .33) than did other basic visual perceptual constructs, possibly because spatial relationships are not completely developed at age 12. Complex and basic visual perceptual skills had medium significant retrospective correlations with grade point average ( r = .40 and r = .41) and first additional language ( r = .30 and r = .33). We concluded that basic and complex visual perceptual constructs remain important for academic achievement in this age-group, while gender and socioeconomic status influence both visual perceptual abilities and academic achievement.

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BACKGROUND: Widespread trends of increasing child obesity are reported in developing countries. This longitudinal NW-CHILD study investigated changes in overweight and obesity over a three year period among 574 children between the ages 6 and 9 (282 boys, 292 girls; 407 black, 143 white) in South Africa (SA), taking into consideration sex, race and school type. Stratified random sampling was used to identify 20 schools, across 5 school SES levels (quintiles), in 4 educational districts of the North West Province of SA. Standard anthropometric techniques and international age adjusted BMI cut-off points for children were used to determine overweight and obesity, 3-years apart. Mixed models were used to analyse the effects of sex, race and socio-economic status (SES) of the school. RESULTS: Overall obesity increased over 3-years by 4% from 12.5% at baseline to 16.7% during follow-up. Obesity increased significantly in both white (4.2%) and black (2.0%) children, although overall prevalence in the final year was double (27.3%) in white children compared to black children (13.3%). Prevalence in obesity increased more in boys (3.2%) compared to girls (2.4%), although girls showed a higher overall prevalence (18.5%). SES effects were significant where children in schools associated with higher SES, had the highest rate of increase and the highest prevalence of obesity. A significant change towards an unhealthy BMI was found in 9.2% of the group over the 3-year period, although a small percentage (3.0%) also transitioned towards a healthier BMI. CONCLUSIONS: Overall obesity prevalence rose significantly from 6-9-years. Obesity, compared to overweight, increased more during this period. Prevalence and rate of increase differed markedly in different sexes, race and SES, masking the extent of the problem. Shifting towards an unhealthy BMI was more common than obtaining a healthier BMI over the 3-year period. It also demonstrated the difficulty of breaking the cycle of obesity, once it had started. Early prevention strategies are needed based on the trends established in this study, with special attention to white children living in high SES regions, and black children in economic transition.

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OBJECTIVES: This study aimed to determine changes and interrelationships between changes in selected anthropometric growth parameters and motor and physical fitness, among boys over a 2 year period during mid-adolescence. METHODS: Speed, agility, hand-eye coordination, explosive power, muscle strength, and aerobic endurance were measured once a year, and the anthropometric measurements (stature, body mass, sitting height, arm span, and sitting height ratio), were measured three times per year, 4 months apart (among 73 adolescent boys). A hierarchical linear model, adjusting for covariates and partial correlation analysis (R(2) ) were used to analyze the data. RESULTS: All anthropometric, motor, and physical measurements improved significantly over the two-year period. Significantly, greater changes were seen between 13 and 14 years in stature, arm span, sitting height and body mass. Changes in muscle strength, speed and agility were mainly significant between 13 and 14 years while the biggest changes occurred in explosive power and upper-body-arm-and-shoulder-strength during year 2 (14-15 years). The majority of interrelationships, indicating moderate to small relationships, were found between changes in stature, arm span, and sitting height, and changing strength, speed, agility, and hand eye coordination over the two-year period, after adjusting for maturity age and physical activity levels. CONCLUSION: Motor and physical fitness improved significantly from 13 to 15 years, showing definite interrelationships with anthropometric growth during the mid-adolescence period. Awareness and education about these changes are recommended as it can have significant effects on the sport performance and fitness training of boys during mid-adolescence.

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The aims of this study were to determine the extent of ocular, motor control problems and the effect of visual therapy on such problems, among seven- to eight-year-old children diagnosed with DCD. Thirty-two, children with a mean age of 95.66 months (SD ± 3.54) participated in the study. The MABC was used to classify children into DCD categories (<15th, percentile) while the Sensory Input Systems Screening Test and QNST-II, were used to evaluate ocular motor control. A two-group pre-test-post-test, cross-over design was followed with a retention test two years, thereafter to determine the lasting effect of the visual therapy, intervention. The 18-week visual therapy programme was executed once a week, for 40 min during school hours, after which the two groups were, crossed over. Percentages of ocular motor control problems ranging, between 6.25% and 93.75% were found in both the groups before participating, in the visual therapy programme, with the highest percentage problems found, in visual pursuit with the left eye. Visual therapy contributed to a, significant improvement of 75-100% in visual pursuit, fixation, ocular, alignment and convergence, with significant lasting effects (p<0.001). Visual therapy is recommended for children with DCD experiencing poor, ocular motor control.

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Objectives: This study aimed to determine the relationship between overweight and obesity and the motor performance of nine- to 13-year-old South African children.Design: The study used a one-way cross-sectional design based on baseline measurements.Settings and subjects: The research group comprised 280 Grade 4; 5 and 6 learners (128 boys and 152 girls) from two schools that represented a distribution of socio-economic status; race and gender.Outcome measures: Anthropometric [(body mass index (BMI) and fat percentage] and motor performance measurements (fine manual control; manual coordination; body coordination and strength and agility) were obtained by means of the Fitnessgram and the Bruininks-Oseretsky Test of Motor Proficiency-II. International age-specific cut-off points were used to classify the children's body composition as normal weight; overweight or obese. Data were analysed by means of descriptive statistics; correlation matrices and analysis of variance; followed by a Tukey post hoc analysis.Results: The results showed that running speed and agility decreased significantly with an increase in BMI. Muscular strength also decreased significantly with a smaller practical significance; while fine manual control; manual coordination; and body coordination showed the weakest relationship to BMI. Analysis of variance showed significant relationships between BMI and running speed and agility (p-value 0.05). These relationships were influenced differently by gender and ethnicity. Conclusion: The motor performance of young South African children was negatively influenced by overweight and obesity. Intervention strategies are recommended to reduce the consequences of overweight and obesity in the overall development of such children

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The high occurrence of overweight and obesity amongst children is a disturbing health problem worldwide. Possible causes of increasing childhood obesity are inactivity and energy imbalances. The aim of this study was to analyse the total energy expenditure (TEE)and physical activity levels in 9-year-old - 12-year-old overweight and obese children during a weekday and a weekend day; as well as during a weekday morning and afternoon. Twenty-four 9-year-old - 12-year-old children (seven boys and 17 girls); of whom nine were overweight and 15 were obese; were selected from seven public primary schools for this study. Body mass index (BMI) cut-off points were used to distinguish between overweight and obese. Each participant wore an ACTICALT monitor to determine their physical activity levels and TEE. It was found that the TEE of the children did not differ between a week day and a weekend day; although the TEE of the week day afternoon differed significantly from that of the weekday morning. Unlike the overweight children; none of the obese children met the requirements of 60 minutes of moderate-intensity physical activity per day. Strategies should be found to increase the activity levels of overweight and; especially; obese children; specifically during the mornings and over weekends

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