Fatigue detection in strength training using three-dimensional accelerometry and principal component analysis

Detection of neuro-muscular fatigue in strength training is difficult, due to missing criterion measures and the complexity of fatigue. Thus, a variety of methods are used to determine fatigue. The aim of this study was to use a principal component analysis (PCA) on a multifactorial data-set based on kinematic measurements to determine fatigue. Twenty participants (strength training experienced, 60% male) executed 3 sets of 3 exercises with 50 (12 repetitions), 75 (12 repetitions) and 100%-12 RM (RM). Data were collected with a 3D accelerometer and analysed by a newly developed algorithm to evaluate parameters for each repetition. A PCA with six variables was carried out on the results. A fatigue factor was computed based on the loadings on the first component. One-way ANOVA with Bonferroni post hoc analysis was calculated to test for differences between the intensity levels. All six input variables had high loadings on the first component. The ANOVA showed a significant difference between intensities (p < 0.001). Post-hoc analysis revealed a difference between 100% and the lower intensities (p < 0.05) and no difference between 50 and 75%-12RM. Based on these results, it is possible to distinguish between fatigued and non-fatigued sets of strength training.     

Pacing,packing and sex-based differences in Olympic and IAAF World Championship marathons

The aim of this study was to describe pacing profiles and packing behaviours of athletes in Olympic and World Championship marathons. Finishing and split times were collated for 673 men and 549 women across nine competitions. The mean speeds for each intermediate 5 km and end 2.2 km segments were calculated. Medallists of both sexes maintained even-paced running from 10 km onwards whereas slower finishers dropped off the lead pack at approximately half-distance. Athletes who ran with the same opponents throughout slowed the least in the second half (P < 0.001, men: ES ≥ 1.19; women: ES ≥ 1.06), whereas other strategies such as moving between packs or running alone were less successful. Overall, women slowed less (P < 0.001, ES = 0.44) and were more likely to run a negative split (P < 0.001), and their more conservative start meant fewer women dropped out (P < 0.001). This also meant that women medallists sped up in the final 2.2 km, which might have decided the medal positions. Marathon runners are advised to identify rivals with similar abilities and ambitions to run alongside provided they start conservatively. Coaches should note important sex-based differences in tactics adopted and design training programmes accordingly.     

西南地区实施《体育与健康课程标准》的实证研究

采用献资料调研、问卷调查等方法了解到西南地区由于封闭的环境制约了西南的经济发展。也使该地区落实《体育与健康课程标准》面临诸多问题，如：学校领导重视体育改革不够，硬、软件落后阻碍，教师、学生自身因素差。据此提出了西南地区未来体育发展措施，为该地区学校体育研究提供参考。     

体育教学中如何对学生进行品德教育

德育教育在中学的体育教学中应用教师的言行 ,不同的教学内容 ,教学环境等多种方法 ,才能收到很好的效果 ,提高教学质量     

斜拉桥索梁锚固区足尺疲劳试验研究

斜拉桥索梁锚固区焊接集中,受力复杂,特别是在运营阶段循环应力作用下的疲劳性能值得关注。本文根据国内某大型斜拉桥中索梁锚固区构造,制作1∶1的索梁锚固区试验模型,进行静力与疲劳试验。根据试验实测数据,研究锚固区关键部位的静力及疲劳受力性能,从而对实桥索梁锚固区结构的可靠性做出评价。     

云南汉族大学生身体素质变化趋势分析与研究

文章对云南省汉族大学生1985,1991,1995年体调五项素质指标进行对比分析．结果表明:1．云南省大学生群体综合素质评价1991年较1985年有下降,1995年比1991年和1985年有提高。2．爆发力、力量及柔韧三指标呈上升趋势,1995年巳超过全国1985年水平,个别指标还优于日本1984年水平,力素质下降明显,速度素质虽有降有升,但1995年仍低于1985年云南水平 。3．多数指标增长值乡>城,除城女力量素质优于乡女外,其余指标均为乡>城。初步分析认为,体育锻炼意识、兴趣和习惯的培养是促进身体素质全面发展的重要举措。     

浅析舞蹈"口传身授、主体参与"课堂教学模式

本文以认知建构论为指导,概括了舞蹈教学的“口传身授,主体参与”的教学模式,总结了其特点和活动程式, 提出了丰富这一课堂教学模式的探索方向。     

酒店员工的工作疲劳问题研究

酒店员工的心理素质、业务素质、工作态度和工作绩效等直接决定着酒店的服务质量,进而关系着酒店的经营成败。当员工在工作中出现疲劳时,会导致工作效率下降,工作失误增多,工伤事故频发等现象,严重的还可能引起员工的生理和心理疾病。研究酒店员工疲劳问题,是酒店人力资源部门当务之急的课题。     

高职院校体育教学课型的重塑

高职院校体育教学课型创新是时代发展的需要。分析高职院校现行体育教学课型的弊端,提出重塑高职院校体育教学课型的构想：一年级“基础课＋选项课”、二至三年级“选项课＋职业特色课”,选修课始终贯穿其中。在此基础上提出实现高职院校体育教学课型重塑的对策和措施。     

现实的个人与人的现实

马克思、恩格斯在批判继承前人思想的基础上提出了“现实的个人”这一概念,“现实的个人”存在于一定的现实社会中,面临着一定的现实的问题。“现实的个人”与人的现实既有密切联系,又有区别,全面正确理解二者,对于促进人的全面自由发展,对于深入领会和正确运用马克思主义原理并在社会实践中发展马克思主义有着重要的意义。