Relationship between weight status and cognition in children: A mediation analysis of physical fitness components

ABSTRACT

Cross-sectional study aimed to analyse differences in cognitive performance across fitness components categories (cardiorespiratory fitness [CRF], speed-agility and muscular fitness [MF]) and weight status in children, and to determine whether physical fitness mediates the association between body mass index (BMI) and cognitive performance. Fitness components and BMI were measured using standard procedures in 630 children aged 5-to-7 years from the provinces of Cuenca and Ciudad Real, Spain. BADyG was used to assess cognitive performance. We used ANCOVA models to test mean differences in cognition scores by BMI and fitness categories. Hayes’s PROCESS macro was used for mediation analyses. Children with normal weight scored better in spatial factor and general intelligence than their overweight/obese peers (p < 0.05), but differences were attenuated when controlling for CRF (p > 0.05). Children with better results in CRF and speed-agility scored better in all cognitive dimensions even after controlling for BMI (p < 0.05). Similarly, children with high MF obtained better scores in verbal factor (p < 0.05). All fitness components acted as mediators of the relationship between BMI and general intelligence (p < 0.05). These findings highlight the crucial role of fitness in minimising the negative effect of excess weight on children’s cognition.

Abbreviations: BMI: Body mass index; CRF: Cardiorespiratory fitness; MF: Muscular fitness; BADyG E1: Battery of general and differential aptitudes; SES: Socioeconomic status; SD: Standard deviation; IE: Indirect effect     

A machine learning approach for automatic detection and classification of changes of direction from player tracking data in professional tennis

ABSTRACT

The purpose of this study was to develop an automated method for identifying and classifying change of direction (COD) movements in professional tennis using tracking data. Three sport science and strength and conditioning experts coded match-play footage of nineteen professional tennis players (9 male and 10 female) from the Australian Open Grand Slam for COD of medium and high intensity. A total of 1,494 changes were identified and aligned with 2D player position sampled at 25 Hz based on camera tracking data. Several machine learning classifiers were trained and tested on a set of 1,128 time-motion features. A random forest algorithm was found to have the best out-of-sample performance, classifying medium and high intensity changes with an F1-score of 0.729. This research offers a novel and applicable way for utilising player tracking data and machine learning techniques to automatically identify and classify COD movements in professional tennis.     

Better Economy on Indoor Track Compared to Treadmill Running With 1% Inclination

ABSTRACT

Purpose: The purpose of this study was to investigate the differences in metabolic responses between the track and the treadmill (1% inclination) running. The latter is recommended for use in laboratory settings to mimic outdoor running. Method: Seventeen male endurance athletes (mean 25.8, s = 3.8 years) performed 4-min running bouts on an indoor track and the treadmill. Results: At all speeds (11, 13, and 15 km·h^?1) athletes showed better economy on the track running compared to the treadmill expressed as oxygen (7.9%, 5.2%, and 2.8%) and caloric (7.0%, 5.3%, and 2.6%) unit cost. Rating of perceived exertion was evaluated substantially higher at all speeds on the treadmill (F(1,16) = 31.45, p < .001, η²_p = .663) compared to running on the track. Participants presented lower heart rate (F(1,16) = 13.74, p = .002, η²_p = .462) on the track at the speed of 11 and 13 km·h^?1 compared to the treadmill, but not at 15 km·h^?1 (p = .021). Conclusions: We conclude that constant inclination (i.e.. 1%) during the treadmill test might not be suitable to reproduce comparable effort to running on the track; rather, there is an optimal treadmill inclination for different intensities to reproduce similar effort compared to the track running.     

以运动服装为主营业务的体育用品制造业上市公司业绩评价——基于DEA视窗分析方法

以2006—2010年为研究期间,选取运动服装为主营业务的体育用品制造业上市公司,采用DEA视窗分析方法,对国内体育用品制造业及国外类似企业的经营效率的变化进行考量。研究发现,国外大型企业阿迪达斯的技术效率一直处于领先地位;国内体育用品制造业上市公司的经营效率与国外的公司有一定的差距,差距主要是由纯技术效率值引起的;国内部分企业的经营效率较高,且金融危机对国内体育用品制造业上市公司影响不大。     

河南省体育竞赛表演市场的开发策略研究

运用文献资料法、"特尔菲"专家问卷调查法、数理统计法等方法,对体育系统职能部门、现场观看体育比赛消费者以及体育界专家学者进行了问卷调查,深入分析河南省体育竞赛表演市场现状,找出目前体育竞赛表演市场存在的问题,结合河南省各地市的实际情况,提出发展河南省体育竞赛表演市场的基本思路与对策(适合开展的体育赛事、有效的营销方法以及未来的发展战略),以促进河南省体育竞赛表演市场快速良性发展。     

合作学习教学模式在网球教学中的实验研究

合作学习20世纪70年代初兴起于美国,它在改善课堂教学的心理气氛、促进学生非智力品质发展、提高学生的学习成绩等方面实效显著。根据合作学习的理论,对体育院系的学生进行网球技术、理论知识掌握、学习兴趣等方面的实验研究,探讨将前沿教育理论应用到体育教学的实践中,为高校体育课程改革和体育教学理论的发展提供参考。     

最佳运动成绩与训练过程若干关系的综合分析

获取最佳运动成绩是运动员训练的最终目标。最佳成绩的取得、提高及维持都需要通过训练过程来实现。训练过程是运动员具有的潜在能力向现实竞技水平转化的时间和空间载体。运动员竞技能力水平的不断发展和训练水平相对滞后这一对矛盾的存在与不断破立,推动着训练过程不断由低级向高级发展。训练过程空间性的特征反映了竞技能力动态平衡的重要性。运动训练中运动员最佳竞技状态的时间越长,最佳运动成绩出现的机率最大。在训练过程中要以最佳成绩为导向,科学规划训练过程。探索最佳成绩出现的特征,推动训练过程发展创造最佳成绩。     

Review on primary and secondary school P.E. teacher＇job performance appraisal

目前,已有的中小学体育教师工作绩效评价研究存在着理论探讨不够深入;评价理念存在偏差;评价内容及标准不够统一且与实践应用还存在差距等一系列问题。未来的研究要树立学科专业思想,从中小学体育教师工作绩效特征出发,重视绩效评价;探讨中小学体育教师工作绩效本身结构维度和内容;重视对体育教师的内在深层次胜任特征的评价;建立健全中小学体育教师国家专业标准,构建中小学体育教师绩效评价体系;结合各学校各地区实际情况选择评价主体与方法,为绩效工资改革、职称制度改革以及学校其他人力资源管理工作提供有力的保障。     

发展柔韧性与运动损伤的预防

在竞技体育不断发展的今天,运动员柔韧性的发展已经引起了运动界的重视。发展运动员良好的柔韧性,可以很大程度上的防护运动员发生不必要的运动损伤,保障运动员持续、系统的训练,从而使运动员的运动成绩稳定的提高,同时还可以有效延长运动员的运动寿命。     

我国竞赛体育表演产品供应链运行机制研究

运用系统分析法和文献资料法对我国竞赛体育表演产品供应链内涵、系统结构、类型和竞赛体育表演产品供应链影响因素以及运行机制等内容进行了研究;竞赛体育表演产品供应链具有横向路线节点少,相对简单;产品生产资料特殊和受经济政治环境影响明显等特征,这使得竞赛体育表演产品供应链类型和运行具有一定的特殊性;供应链成员目标不一致、信息不畅、个体和整体利益冲突以及核心企业地位缺失等因素造成了我国竞赛体育表演产品供应链的发展相对滞后;通过建立联合决策机制,综合激励考评机制,战略合作伙伴关系和契约机制,完善运动员的利益保障机制和完善供应链成员间信息沟通机制来共同协调我国竞赛体育表演产品供应链运行。