Effects of a verbal and visual feedback system on running technique,perceived exertion and running economy in female novice runners

The purpose of this study was to determine the effects of a verbal and visual feedback system on running technique, ratings of perceived exertion (RPE), and running economy. Twenty‐two female novice runners were randomly assigned to experimental (n = 11) and control (n = 11) groups. The experimental subjects received verbal and visual feedback concerning their running technique prior to and during each training run. Training involved 15 20‐min treadmill running sessions over a 5‐week period. The control group adhered to the same training routine but did not receive feedback concerning their running technique. High‐speed (100 Hz) photography was used to collect biomechanical data. A submaximal oxygen consumption test and Borg's RPE scale were used to collect data concerning running economy and perceived exertion, respectively. Statistical analysis using ANCOVA revealed that the proposed feedback system had a significant (P < 0.01) effect on the experimental group's running technique by affecting the following desired changes relative to the control group: greater relative stride lengths, shorter support time, greater ankle dorsiflexion during support and greater knee flexion during support and non‐support. There were no significant differences between the groups in submaximal VO₂ or RPE. The results of this study suggest that verbal and visual feedback are effective means of eliciting modifications in running style in female novice runners. The link between modifications in running style and improvements in running economy and perceived exertion remains unclear.     

Reproducibility of two electrical stimulation techniques to assess neuromuscular fatigue

Abstract

The main aim of this study was to compare the reliability of percutaneous electrical stimulation over the muscle (MES) and electrical stimulation over the nerve (NES) to assess quadriceps muscle voluntary activation and muscle contractile properties. A secondary aim was to determine whether MES detects the fatigue induced by prolonged exercise in the heat. For the first purpose, eight participants performed on three non-consecutive days: quadriceps maximal voluntary contractions (MVC) with superimposed electrical stimulation to assess voluntary activation, and electrically evoked contractions to assess peak force (P_EVO), using NES (ball-shaped cathode) or MES (adhesive electrodes). For the second purpose, the same participants pedalled for 2 h at 60% VO_2max in a 36°C environment. Quadriceps maximal voluntary contractions, voluntary activation, and P_EVO were measured before and just after the completion of exercise using MES. Voluntary activation assessed with MES presented lower intra-day (1.3±0.2 vs. 2.5±0.5%) and inter-day (1.7±0.3 vs. 2.9 ±0.4%) coefficients of variation than with NES. P_EVO had lower intra-day and inter-day coefficients of variation (5.6±1.0 vs. 17.0±3.3%) and higher intraclass correlation values (ICC 0.95 vs. 0.85) when using MES than with NES either when stimulating at 20 or 80 Hz. Prolonged exercise in the heat reduced MVC (11±2%) and quadriceps muscle voluntary activation (5.2±0.5%) from pre-exercise values (P<0.05), as previously found. P_EVO was unaffected by exercise in the heat. In conclusion, MES is more reliable than NES to assess quadriceps muscle voluntary activation and P_EVO. In addition, MES readily detects the reduction in voluntary activation induced by prolonged exercise in the heat.     

赛场噪声对运动时身体机能的影响

赛场噪声影响运动员运动效能这人问题一直深受人们的关注。分析赛场噪声的来源与特点，并着重从听觉、心血管、神经、内分泌系统和物质代谢等五个方面论述赛场噪声对运动时身体机能的影响，提示赛场噪声刺激可加速运动时疲劳的产生，影响运动能力的正常发挥。     

"运能补剂"消除运动性疲劳的研究

"运能补剂"是针对体能性项目运动员疲劳的特点,采用中医益气补血、健脾和胃、养心安神的手段,研制的一种纯中药制剂.主治运动员大负荷训练期出现的失眠多梦、食欲不振、神疲乏力等征,有效地促进运动性疲劳的消除,加快运动员体力的恢复.     

从后现代主义的视角审视当代幼儿体育教育

运用后现代主义理论审视当代幼儿体育教育,从教育思想、教学内容、组织形式、师生关系等几方面重新思考和定位幼儿体育,构建后现代背景下的幼儿体育教育模式.     

脑力、体力劳动者足底压力参数分布特征及评定

通过分析脑力、体力劳动者自然行走过程中峰力值（maxforce,MF）、达峰力值时间（time to max force）、冲量（impulse）等参数特征,探讨职业对足底压力分布的影响。采用比利时Footscan USB2平板式足底压测试系统对50名普通健康脑力劳动者和63名普通健康体力劳动者进行自然行走过程中动态足底压力测试。结果显示：脑力、体力劳动者左脚Toel、Toe2-5、Heel Lateral区域平均峰值（MF）存在显著性差异,右脚Mid foot、Meta5区域MF差异存在非常显著性（P〈0．01）,左、右双足平均峰力值（MF）最大值均出现在足跟内侧（Heel Medial）。脑力、体力劳动者足底各区域达峰力值的时间（TMF）,左右双足差异均存在非常显著性（P〈0．01）。脑力劳动者与体力劳动者行走过程中左足在Toel、Toe2-5、Meta1、Heel Medial、Heel Lateral区域的冲量（Impulse,IP）,体力劳动者明显大于脑力劳动者且具有显著性差异〈0．01）,体力劳动者与脑力劳动者的足底MF与足弓接触面积及足角度存在不同程度的相关。结果说明：脑力劳动者与体力劳动者行走过程中左右双足的平均峰力值、接触面积、冲量等参数都存在不同程度的差异,可能与长期从事的职业不同有关,建议经常进行体育锻炼或定制矫形鞋垫,可以缓解足底压力高压区的过度集中,不断维护足健康水平。     

系统科学视角下的优秀散打运动员体能系统运行机制及训练控制的研究

以系统科学基本原理为指导对优秀散打运动员体能训练问题进行了研究,研究内容主要包括优秀散打运动员体能系统的结构、运行机制和体能训练控制方式。体能系统框架结构与运行结构是开展其他研究的基础;适应是体能系统演化和发展的根源,体能系统运行机制有标识、响应和积木机制;通过反馈控制方式对优秀散打运动员进行体能训练,提高运动员神经系统对体能系统其他子系统的控制与协同能力。     

高校体育教师教学监控能力的培养

采用角色改变技术、教学反馈技术和现场指导技术3种方法做为干预手段，探讨了干预条件下高校体育教师教学监控能力的提高与学生学科能力发展之间的关系。经过一个学年的干预训练，结果表明：(1)角色改变技术、教学反馈技术和现场指导技术做为3种干预手段，能明显地促进高校体育教师教学监控能力发展；(2)高校体育教师教学监控能力的发展，会促进其教学认知水平的提高和教学行为的改善；(3)高校体育教师教学监控能力的发展有利于促进学生学科能力的发展，提高学生的学业成绩。