A cross-sectional study on the deprivation and sex differences in health-related fitness measures in school children

ABSTRACT

This study aimed to investigate deprivation and sex differences in selected health-relatedfitness measures in 9-12-year-old children. Data were captured on 3,407 children (49.3% boys; aged 10.5 ± 0.6 years). Cardiorespiratory fitness(20 m multistage shuttle run test; 20 m MSRT), muscular strength (handgrip strength) and body mass index (BMI) were measured. Welsh Index of Multiple Deprivation (WIMD) scores were used to make quintile groups. A two-way Analysis of Variance examined differences in BMI z-score by sex and WIMD quintiles. Two-wayAnalysis of Covariances investigated the effect of sex and WIMD quintiles on grip strength and shuttles achieved in 20 m MSRT, adjusting for BMI z-score and maturation, repectively. Independent of sex, children in the middle quintile had a significantly higher mean BMI z-score (p = 0.029) than their least deprived counterparts. There was a significant increase in grip strength (p = 0.005) and20 m MSRT (boys p < 0.001; girls p = 0.028) between most and least deprived quintiles. Significant differences in 20 m MSRT score were more apparent with decreases in deprivation in boys.Overall, inequalities exist in health-related fitness by sex and deprivation. These results can be used to inform focused services to improve current and future health.     

Effects of age,sex and activity level on counter-movement jump performance in children and adolescents

Abstract

The aim of this study was to investigate counter-movement jump performance and its reliability in children and adolescents with respect to age, sex and activity level. We tested 1835 children and adolescents aged between 4 and 17 years. All participants performed three counter-movement jumps on a force platform with arms akimbo. The participants were divided into six age groups and subdivided by sex within each group, to analyse age and sex effects. Subsequently, jumping performance of active and sedentary participants was compared. Jump height was calculated and the highest jump out of three was used for the calculations of peak force and peak rate of force development. Variability of all parameters was quantified using the coefficient of variation over all jumps. Jump height increased significantly with increasing age while peak rate of force development decreased. Peak force was similar for all age groups. Jump height was significantly higher in male participants and peak force and peak rate of force development was significantly lower in male participants. Variability of jump height and peak force decreased significantly with increasing age leading to reliable data above the age of 10 years. Peak rate of force development showed a high variability and, therefore, should be interpreted with caution. This could be useful information for coaches as they need to know from which age onwards the counter-movement jump is applicable in performance diagnostics and which parameters are sensible for interpretation. Finally, the present study provides data to be used as normative references.     

Age and gender interactions in short distance triathlon performance

Abstract

This study investigated the participation and performance trends as well as the age and gender interaction at the Olympic distance ‘Zürich Triathlon’ (1.5?km swim, 40?km cycle and 10?km run) from 2000 to 2010 in 7,939 total finishers (1,666 females and 6,273 males). Female triathletes aged from 40 to 54 years significantly (P?<?0.05) increased their participation while the participation of younger females and males remained stable. Males of 50–54 years of age and females of 45–49 years of age improved their total race time. For elite top five overall triathletes, mean gender differences in swimming, cycling, running and overall race time were 15.2?±?4.6%, 13.4?±?2.3%, 17.1?±?2.5%, and 14.8?±?1.8%, respectively. For both elite and age group athletes, the gender difference in cycling time was significantly (P?<0.001) lower than for swimming and running. The gender difference in overall Olympic distance triathlon performance increased after the age of 35 years, which appeared earlier compared to long distance triathlon as suggested by previous studies. Future investigations should compare gender difference in performance for different endurance events across age to confirm a possible effect of exercise duration on gender difference with advancing age.     

加强学前体育对幼儿身体机能素质影响的实验研究

1弓1言科学地开展学前体育,增强幼儿体质,不仅关系到幼儿在整个学前阶段能否健康成长,也是激发幼儿的体育兴趣,培养他们进行终身体育锻炼能力的重要步骤。但是,当前人们对学前体育的认识还不够,重文化知识培养,轻体育锻炼能力培养的现象还比较普遍。许多幼儿在学前阶段没能掌握基本的体育活动技能,也无法充分感受体育游戏的快乐。本文通过对系统学前体育教育及作为对照班的幼儿进行身体机能及素质测试,试图展现加强学前体育在提高幼儿身体机能与素质方面的积极作用,为更加系统。规范、科学地实施学前体育提供实验依据。2研究对象…     

"Show and tell" in the gymnasium revisited: developmental differences in modeling and verbal rehearsal effects on motor skill learning and performance.

Little research has investigated the observational learning process from a developmental perspective. The purpose of this study was to extend previous research by considering two factors: performance versus learning and sequencing versus form scores. Children (N = 60) comprising two age groups (5-0 to 6-11 and 8-0 to 9-11 years) were randomly assigned to verbal rehearsal only, model only, or model plus verbal rehearsal conditions. The task was a 6-part motor skill sequence in which proper sequencing and quality of form were assessed. A 2 x 3 x 4 (age group by model type by trial blocks) repeated measures MANOVA revealed a significant three-way interaction. Older children performed equally well under any of the model type conditions during both performance and learning. For younger children, a model plus rehearsal was superior to rehearsal only on sequence and form at performance and learning and superior to model only on sequence scores during the first two performance trial blocks. Model only and model plus rehearsal conditions were equally effective on form scores. These results suggest that age differences exist in the modeling of motor skills under conditions varying in model type, sequence and form scores, and performance and learning phases.     

In search of the loci for sex differences in throwing: the effects of physical size and differential recruitment rates on high levels of dart performance

Contemporary accounts of sex differences in perceptual-motor performance differ in their emphasis on nature and nurture. Study 1 examined the effect of extensive training on one of the largest sex differences, namely accuracy in dart throwing, and found that physical differences in height and reach could not explain sex differences in regional/national level dart players. Study 2 rejected accounts of sex differences based on participation rates by showing that male players recruited from a relatively small pool of club players were superior to the best female players selected from a much larger pool at the international level. Alternative accounts of the source of sex differences in darts, based on male and female players' differential development and practice histories, are discussed.     

Precompetitive anxiety and motor performance: a psychophysiological examination

Male volunteer subjects (27) completed a 5-week habituation period during which practise was undertaken on three motor performance tests. Tests were of serial reaction time, visuomotor ability and muscular power. Following stabilization of performance subjects entered an experimental period where they performed the tests before an evaluative audience on one occasion, and against a matched opponent, also before an evaluative audience on the final occasion. Preperformance measures were obtained of neuroendocrine activity, anticipatory heart rate and state anxiety. Significant precompetition elevations in state anxiety, heart rate and adrenaline levels were observed, supporting the notion that the exposure was perceived as stressful by subjects. Significant correlations were obtained between adrenaline levels and both state and trait anxiety scores. Results showed a significant increase in performance compared to habituation levels for all three tests in the audience condition. In the competitive situation against a matched opponent, performance level for the visuomotor and power tests declined significantly compared to the previous session performed before an audience. Serial reaction time performance showed a continuing upward trend, although failing to achieve significance. Changes in performance are discussed with reference to cue-utilization explanations and broader cognitive resource limitations.     

Evidence for biomechanics and motor learning research improving golf performance

The aim of this review was to determine how the findings of biomechanics and motor control/learning research may be used to improve golf performance. To be eligible, the biomechanics and motor learning studies had to use direct (ball displacement and shot accuracy) or indirect (clubhead velocity and clubface angle) golf performance outcome measures. Biomechanical studies suggested that reducing the radius path of the hands during the downswing, increasing wrist torque and/or range of motion, delaying wrist motion to late in the downswing, increasing downswing amplitude, improving sequential acceleration of body parts, improving weight transfer, and utilising X-factor stretch and physical conditioning programmes can improve clubhead velocity. Motor learning studies suggested that golf performance improved more when golfers focused on swing outcome or clubhead movement rather than specific body movements. A distributed practice approach involving multiple sessions per week of blocked, errorless practice may be best for improving putting accuracy of novice golfers, although variable practice may be better for skilled golfers. Video, verbal, or a combination of video and verbal feedback can increase mid-short iron distance in novice to mid-handicap (hcp) golfers. Coaches should not only continue to critique swing technique but also consider how the focus, structure, and types of feedback for practice may alter learning for different groups of golfers.     

技能主导类表现难美性项群制胜规律同异分析

从整体、局部、专项3个层次对技能主导类表现难美性项群制胜规律进行分析.认为:整体层次,技能主导类表现难美性项群共同制胜因素是难与稳的矛盾博弈,制胜因素间本质联系是实力和谋略随机应变下的难度战术运用;局部层次,技能主导类表现难美性项群的3个类别是难度和成套创编艺术性权衡;专项层次,每个项目有独特的制胜因素,如竞技...     

Explaining differences in the metabolic cost and efficiency of treadmill locomotion in children

The metabolic cost of locomotion at any given speed, when expressed per kilogram of body mass, is greater for children than for older individuals. Incomplete explanations for the age-related difference motivated this study, which used a multidisciplinary method to examine metabolic, kinematic and electromyographic data from three maturational groups of children. Thirty children aged 7-8 (n = 10), 10-12 (n = 10) and 15-16 (n = 10) years completed 4 min bouts of submaximal treadmill exercise at six speeds--two walking and four running--assigned in random order. Metabolic (net VO2), kinematic (total body mechanical power, energy transfer rates, stride rate) and electromyographic (co-contraction of agonist and antagonist muscles in thigh and leg segments) data were collected. Multiple regression analysis was performed with net VO2 or efficiency as the dependent variable and mechanical power, thigh and leg co-contraction, stride rate and age as independent variables. It was possible to explain up to 77% of the age-related variance in net VO2 and 62% of the variation in efficiency using combinations of these variables. Age was the best single predictor of both VO2 and efficiency. Co-contraction, possibly used to enhance joint stability, was an important component of the observed age-related differences, although mechanical power was not. Additional variance might be explained as specific growth-related factors affecting the metabolic cost of locomotion are identified, as mechanical work models improve, and as methods are developed to measure the effects of stored elastic energy and the metabolic cost of isometric muscle actions.     

Individual differences in visual information processing rate and the prediction of performance differences in team sports: a preliminary investigation.

This study used a backward-masking paradigm to examine individual differences in rate of visual information processing among university basketball, ice hockey and Canadian football players. Displays containing four letters were presented for stimulus durations ranging from 25 to 300 ms. Following stimulus offset, a masking stimulus was presented for 200 ms. The subjects were instructed to write down as many letters as possible from the briefly presented stimulus display on a specially prepared response grid. The results indicated consistent individual differences in rate of visual information processing. More importantly, it was found that rate of visual information processing as indexed by the backward-masking technique, has promising validity for predicting general performance excellence in university ice hockey and basketball players. Individual differences in rate of visual information processing were interpreted as reflecting the operation of attentional factors.     

大肌肉动作发展位移分测试性别差异之研究

1前言动作是人类适应环境的重要手段,也是个体发育、成长必不可少的活动能力。儿童早期的动作发展,不仅会影响个体成长后动作技能的学习和发展,还会影响个体的认知发展、心理发展和社会交往等多方面能力的发展。而大肌肉动作的发展是个体动作发展的重要组成,是各类感知觉动作的     

Influence of a motor skill intervention on fundamental motor skill development of disadvantaged preschool children

The influence of a 12-week (24, 45-min motor sessions) motor skill intervention on fundamental motor skill (FMS) development of disadvantaged preschools was examined. Pre-and postintervention measures of the object control (OC) and locomotor subscales of the Test of Gross Motor Development were obtained for both groups. Prior to the intervention, developmental delays in FMS were reported. Two separate 2 x 2 (Group x Pre-Postintervention) analyses of variance with repeated measures yielded a significant Group x Pre-Postintervention interaction for locomotor, F(1, 57) = 134.23, p = .000, h2 = .70, and OC, F(1, 57) = 161.55, p = .000, h2 = .74) skills. Compared to the Control group, the motor skill intervention group revealed significant higher locomotor and OC scores following the intervention than prior to the intervention.     

State anxiety and motor performance: testing the conscious processing hypothesis

Previous research has argued that skills acquired explicitly are more likely to fail under stressful conditions than skills that have been learned implicitly. The present study addressed an alternative explanation for the robustness under stress of implicit task performance. As implicit learners acquired the skill of golf putting while generating random letters, it is possible that they became desensitized to self-generated verbalizations and thus immune to the effects of competitive anxiety. We tested this interpretation while controlling for a further rival hypothesis generated by Eysenck's Processing Efficiency Theory. We also examined the effect of increased state anxiety on the kinematic processes underlying performance breakdowns. For task performance, we found evidence that partially supported the conscious processing hypothesis, while the results of the kinematic analysis of the putting stroke were equivocal. Analysis of self-reported effort scores provided partial support for processing efficiency theory.     

Gross motor skills and sports participation of children with visual impairments

Gross motor skill performance of children with visual impairments and its association with the degree of visual impairment and sports participation was examined. Twenty children with visual impairments (M age = 9.2 years, SD = 1.5) and 100 sighted children (M age = 9.1 years, SD = 1.5) from mainstream schools participated. The results showed that children with visual impairments had significantly lower object control but not locomotor skill scores than the sighted children. No significant differences were found between children with a moderate and severe visual impairment. Children with visual impairments who participated in sports had significantly higher object control skill scores than those who did not. No significant associations between motor skills and sports participation were found in the sighted children.     

Developmental modeling effects on the quantitative and qualitative aspects of motor performance

The purpose of the present experiment was to replicate and extend previous developmental modeling research by examining the qualitative as well as quantitative aspects of motor performance. Eighty females of two age groups (5-0 to 6-6 and 7-6 to 9-0 years) were randomly assigned to conditions within a 2 x 2 x 2 (Age x Model Type x Rehearsal) factorial design. Children received either verbal instructions only (no model) or a visual demonstration with experimenter-given verbal cues (verbal model) of a five-part dance skill sequence. Children were either prompted to verbally rehearse before skill execution or merely asked to reproduce the sequence without prompting. Both quantitative (order) and qualitative (form) performances were assessed. Results revealed a significant age main effect for both order and form performance, with older children performing better than younger children. A model type main effect was also found for both order and form performance. The verbal model condition produced better qualitative performance, whereas the no model condition resulted in better quantitative scores. These results are discussed in terms of differential coding strategies that may influence task components in modeling.