Physical activity profiles and selected muscular fitness variables in English schoolchildren: A north–south divide?     

Lee Ingle  Ashlie Stephenson  Gavin R. Sandercock 《European Journal of Sport Science》2016,16(8):1187-1196

The aim of the study was to compare and contrast habitual physical activity (PA) profiles and muscular fitness in schoolchildren from northern and southern regions of England. Data were collected from two secondary schools in the north east (NE) of England. The study procedures followed methods employed by the East of England Healthy Hearts Study in 10–16-year-old boys and girls based in the south east (SE) region of England and data were compared. Habitual physical activity (PAQ-A), vertical jump test, and hand-grip (HG) strength were assessed. We converted raw scores from all assessments to age- and sex-normalised z-scores. We recruited 597 children (58% boys) in the NE and compared findings to 597 age- and sex-matched boys and girls from the SE. Boys in the SE had significantly stronger HG scores, jumped higher, were more powerful (mean peak power: 2131?W vs. 1782?W; P?P?P?相似文献   

Low-intensity electrical muscle stimulation induces significant increases in muscle strength and cardiorespiratory fitness     

Toshiaki Miyamoto  Hiroyuki Kamada  Akira Tamaki  Toshio Moritani 《European Journal of Sport Science》2016,16(8):1104-1110

The aim of this study was to investigate the effect of low-intensity exercise training using belt electrode skeletal muscle electrical stimulation on muscle strength and cardiorespiratory fitness in healthy subjects. Nineteen healthy subjects were allocated into control or intervention groups; in both groups the participants kept regular physical activity while the intervention group underwent 30 min B-SES training at 3–4 METs for four weeks. Knee extensor muscle strength and cardiorespiratory endurance during incremental exercise test were measured at baseline and after four weeks for all participants. The relative change of knee extensor muscle strength in the intervention group was significantly higher than control group (p?p?相似文献   

Effects of load mass carried in a backpack upon respiratory muscle fatigue     

Mark Faghy  Sam Blacker  Peter I. Brown 《European Journal of Sport Science》2016,16(8):1032-1038

Purpose: The purpose of this study was to investigate whether loads carried in a backpack, with a load mass ranging from 0 to 20?kg, causes respiratory muscle fatigue. Methods: Eight males performed four randomised load carriage (LC) trials comprising 60?min walking at 6.5?km?h^?1 wearing a backpack of either 0 (LC₀), 10 (LC₁₀), 15 (LC₁₅) or 20?kg (LC₂₀). Inspiratory (P_Imax) and expiratory (P_Emax) mouth pressures were assessed prior to and immediately following each trial. Pulmonary gas exchange, heart rate (HR), blood lactate and glucose concentration and perceptual responses were recorded during the first and final 60?s of each trial. Results: Group mean P_Imax and P_Emax were unchanged following 60-min load carriage in all conditions (p?>?.05). There was an increase over time in pulmonary gas exchange, HR and perceptions of effort relative to baseline measures during each trial (p?p?>?.05). Conclusions: These findings indicate that sub-maximal walking with no load or carrying 10, 15 or 20?kg in a backpack for up to 60?min does not cause respiratory muscle fatigue despite causing an increase in physiological, metabolic and perceptual parameters.  相似文献   

钢结构材料在高温(火灾)条件下的力学性能试验研究     

魏瑞演 《福建工程学院学报》2002,(1)

从基本的钢结构材料在高温下的力学性能着手 ,进行高温条件下钢结构材料的性能试验 ,建立高温下钢材的屈服强度、极限强度、弹性模量和极限应变随温度变化的力学模型 ,为高温 (火灾 )条件下钢结构的结构分析提供依据。  相似文献   

对高水平男子跳高运动员专项力量训练手段的研究     

张红霞 《滨州学院学报》2006,22(6):86-88

运用文献资料法、问卷调查法、统计分析等方法,对高水平男子跳高运动员专项力量训练手段进行统计研究,遴选出常用的、功效性高的专项力量训练手段18项,并将其分为爆发力、支撑力量、起跳力量、摆动力量和腹(背)肌力量5类,为男子跳高运动员专项力量的训练提供有价值的参考.  相似文献   

从后殖民视角看文化失衡对翻译的影响     

聂咏华 《丽水学院学报》2006,28(3):45-48

传统的翻译研究把翻译活动假想成一个在真空中进行的活动,但翻译作为一种文化交流的形式,不可避免地要受到意识形态、历史、政治、经济等外部因素的影响。尤其是处于不同地位的文化交流,其表现就更为明显。全文从后殖民的角度来探讨文化失衡对翻译流量、选材及翻译策略的影响。  相似文献   

篮球专项力量训练的研究     

刘革  张海灵 《牡丹江教育学院学报》2007,(3):92-93

篮球运动员的力量训练应注重弹跳力、腰背部肌肉力量、小腿肌群力量和手臂、手腕、手指力量的发展.该研究从篮球专项力量训练的理论基础、训练方法的选择、需要注意的问题等方面进行了分析,为篮球专项力量的训练提供了重要参考.  相似文献   

Cr3锻钢平整工作辊"桔皮"原因分析及改进措施     

吴国胜  栗晓  游涛  姚炳强 《武汉工程职业技术学院学报》2005,17(4):14-17

某热轧带钢厂Cr3材质锻钢平整工作辊每次上机服役仅生产1000t钢卷即需换辊修磨，严重影响产品质量和轧辊使用寿命。对Cr3材质锻钢工作辊进行硬度、金相组织等检验发现，虽然辊面金相组织正常，但是硬度偏低，导致在使用过程中出现塑性变形，表明这种材质的工作辊不适合在“干”平整的工况条件下用作热轧平整工作辊。建议采用具有更高耐磨性、更高热稳定性的高速工具钢、半高速工具钢和改进型高NiCr无限冷硬铸铁工作辊等材质工作辊代替Cr3材质锻钢工作辊，以提高生产效率和轧辊寿命。  相似文献   

论杠杆原理在体育实践中的应用     

陈彩虹 《渭南师范学院学报》2011,26(6):74-76

杠杆原理在运动员选材中的应用主要着重于先天性因素中身体形态的测量及其比例关系;力量训练中,可用增加阻力和延长阻力臂的手段来发展肌力;在不同运动项目中主要起到维持平衡、增速和省力的作用.  相似文献   

海水冻融和侵蚀耦合作用下混凝土破坏面演化模型     

张峰  李树忱  叶见曙  李守凯 《东南大学学报》2011,(2):206-209

为了有效评估海水冻融与侵蚀后混凝土的力学性能,基于大型静态和动态刚度伺服压力机进行了混凝土冻融和海水侵蚀后的力学性能试验.对混凝土进行了50,100,200和300次冻融循环,并配置了人工海水;选择了合理的干湿循环机制,对冻融后的混凝土试块进行了10,20,30,40,50和60次干湿循环.对混凝土弹性模量和抗压强度退...  相似文献