SRM系统在短距离自行车专项能力测试与评定中的应用研究

应用场地SRM系统对上海自行车队重点队员6人的场地专项训练分阶段进行跟踪测试,以便筛选有效指标评价短距离自行车主要专项能力。结果表明,在短距离自行车爆发力评价中,最大功率和平均功率、最大频率和平均频率是反映运动能力的有效指标;平均功率和平均频率是反映力量耐力的有效指标;在对短距离自行车专项最大速度的评价中,最大频率和平均频率是反应运动能力的有效指标;而平均频率是反映高速耐力的有效指标。     

测量可靠性及其估价方法分析

测量的可靠性是评价测量质量的重要指标。一般认为测量的可靠性代表测量结果的准确性，这显然是一种误解，尤其是目前应用较多的几种可靠性估价方法似乎无法对可靠性作出正确的估价。为此，对于可靠性及其估价方法应重新加以审视和评析，以期重新认识并有所改善。通过分析和示例结果，可以得出如下结论：测量的可靠性不能完全表达测量结果的准确度；在可靠性定义中一致性不能由相关或相似性替代；在进行差异分析时，应注意重复测量结果的关联属性，并推荐使用非参数检验方法；可靠性分析不能替代误差分析与处理等其他方法。     

发展短中距离自行车运动员专项力量素质的探讨

结合自行车运动训练实践 ,阐述自行车中短距离运动员力量训练的方法与途径和自行车专项力量训练的解剖学与动力学特点 ,并针对运动员的专项训练特点和与肌肉快速收缩规律 ,提出自行车专项力量训练原则性构思及应采取的有效训练手段     

自行车运动员连续多日赛对心率变异性的影响及果糖的疲劳恢复作用

以中国优秀女子公路自行车运动员为研究对象,研究长期比赛对她们心率变异性的影响,探讨心率变异性（HRV）早期诊断心脏疲劳的实效性,同时对1,6-二磷酸果糖（FDP）的营养干预效果做动态观察。连续30天的多日赛后总体心率变异性没有产生明显改变,比赛＋果糖组比赛后心率变异性和比赛组相比,也没有明显区别。说明在本赛季连续30天的多日赛对心脏的交感和副交感神经支配都未产生明显影响。磷酸果糖对心脏的营养干预作用不明显。     

自行车运动员进行功率自行车3种递增负荷运动实验比较有氧耐力研究

目的:通过40名自行车专业运动员在功率自行车上进行3种递增负荷运动实验比较有氧耐力.方法:40名自行车运动员(男21,女19)在功率自行车上进行有氧力竭运动,分别采用3 min递增法、1 min递增法和线性递增法进行运动负荷递增,用Oxyam Pro运动心肺功能仪观察最大耗氧量(VO2max)、心率(HRmax)、呼吸商(RQ)等指标,运动前、后采集血乳酸(Lac).结果:3种递增负荷运动实验的VO2max、HRmax指标无显著性差异(P>0.05),3种实验的RQ、Lac指标差异无显著规律性.结论:自行车运动员进行功率自行车3种递增负荷运动实验比较有氧耐力没有统计学差异,3种递增负荷运动实验均可作为功率自行车进行有氧耐力测试的方法.     

The validity and reliability of a sample of 10 Wattbike cycle ergometers

ABSTRACT

The purpose of the study was to assess the validity and inter-bike reliability of 10 Wattbike cycle ergometers, and to assess the test–retest reliability of one Wattbike. Power outputs from 100 to 1000 W were applied using a motorised calibration rig (LODE) at cadences of 70, 90, 110 and 130 rev · min^?1, which created nineteen different intensities for comparison. Significant relationships (P < 0.01, r² = 0.99) were found between each of the Wattbikes and the LODE. Each Wattbike was found to be valid and reliable and had good inter-bike agreement. Within-bike mean differences ranged from 0.0 W to 8.1 W at 300 W and 3.3 W to 19.3 W at 600 W. When taking into account the manufacturers stated measurement error for the LODE (2%), the mean differences were less than 2%. Comparisons between Wattbikes at each of the nineteen intensities gave differences from 0.6 to 25.5 W at intensities of 152 W and 983 W, respectively. There was no significant difference (P > 0.05) between the measures of power recorded in the test–retest condition. The data suggest that the Wattbike is an accurate and reliable tool for training and performance assessments, with data between Wattbikes being able to be used interchangeably.     

Reliability of the virtual elevation method to evaluate rolling resistance of different mountain bike cross-country tyres

Although a low rolling resistance is advantageous in mountain bike cross-country racing, no studies have used the virtual elevation method to compare tyres from different manufacturers as used in international competitions so far. The aims of this study were to assess the reliability of this method, to compare the off-road rolling resistance between tyres and to calculate the influence on off-road speed.

Nine 29-in. mountain bike cross-country tyres were tested on a course representing typical ground surface conditions 5 or 6 times. The coefficient of rolling resistance was estimated with the virtual elevation method by 3 investigators and corresponding off-road speeds were calculated.

The virtual elevation method was highly reliable (typical error = 0.0006, 2.8%; limits of agreement <0.0005, r ≥ 0.98). The mean coefficient of rolling resistance was 0.0219 and differed from 0.0205 to 0.0237 (P < 0.001) between tyres. The calculated differences in off-road speed amounted to 2.9–3.2% (0% slope) and 2.3–2.4% (10% slope) between the slowest and the fastest tyre.

The reliability of the method and the differences in rolling resistance between the tyres illustrate the value of testing tyres for important competitions on a representative ground surface using the virtual elevation method.     

Reliability of the Heart Rate Response to Submaximal Upper and Lower Body Exercise

Abstract

This investigation was conducted to compare the influence of high and low perceived competence (PC) and various causal dimension orientations on expectations, persistence, and performance while perceiving failure on a motor task. Based on a response to a PC scale, 84 junior high school students were selected to participate in this study. Separately, 42 low and 42 high PC subjects were oriented to perceive their performance on a stabilometer balancing task as due to: (a) internal, controllable, unstable factors (ICU); (b) internal, uncontrollable, stable factors (IUS); or (c) nothing in particular (NDO). Subjects then received fictitious negative feedback over 15 trials. Results revealed that persistence, expectations, and performance dependent measures were significant for PC and Causal Dimension groups. More specifically, the High PC group persisted longer, had higher expectations, and performed significantly better than the Low PC group. Furthermore, the subjects presented ICU orientations persisted for a longer amount of time, revealed higher expectations over trials, and performed significantly better over trials than the subjects in the IUS and NDO groups. These findings suggest that perceived competence and causal dimensional orientations influence children's expectations, persistence, and performance when perceiving failure on a motor task.     

Vibrotactile feedback for correcting aerodynamic position of a cyclist

ABSTRACT

Guidance to maintain an optimal aerodynamic position is currently unavailable during cycling. This study used real-time vibrotactile feedback to guide cyclists to a reference position with minimal projected frontal area as an indicator of aerodynamic drag, by optimizing torso, shoulder, head and elbow position without compromising comfort when sitting still on the bike. The difference in recapturing the aerodynamic reference position during cycling after predefined deviations from the reference position at different intensities was analysed for 14 participants between three interventions, consisting of 1) vibrotactile feedback with a margin of error of 1.5% above the calibrated reference projected frontal area, 2) vibrotactile feedback with a margin of 3%, and 3) no feedback. The reference position is significantly more accurately achieved using vibrotactile feedback compared to no feedback (p < 0.001), but there is no significant difference between the 1.5% and 3% margin (p = 0.11) in terms of relative projected frontal area during cycling compared to the calibrated reference position (1.5% margin ?0.46 ± 1.76%, 3% margin ?0.01 ± 2.01%, no feedback 2.59 ± 3.29%). The results demonstrate that vibrotactile feedback can have an added value in assisting and correcting cyclists in recapturing their aerodynamic reference position.     

游泳动态阻力测试方法探蹊

以自行研制的动态阻力测试仪器探索了一种测量动态阻力的实验方法。通过蛙泳收腿动作划分2阶段的测试和计算后指出:动态阻力受速度的变化影响较小;在较高运动速度下静态阻力占总阻力的比例稍高;动态阻力占总阻力的比例随运动速度的下降而提高。     

Reliability assessment and correlation analysis of 3 protocols to measure trunk muscle strength and endurance

Different methods have been developed to quantify trunk muscle strength and endurance. However, some important protocol characteristics are still unclear, hindering the selection of the most suitable tests in each specific situation. The aim of this study was to examine the reliability and the relationship between 3 representative tests of the most common type of protocols used to assess trunk muscle strength and endurance. Twenty-seven healthy men performed each test twice spaced 1 month apart.Trunk strength and endurance were evaluated with an isokinetic dynamometer and 2 field tests including Biering-Sørensen test and Flexion–rotation trunk test.

All tests showed a good relative consistency (intraclass correlation coefficient [ICC]> 0.75), except for the isokinetic endurance variables which had low–moderate reliability (0.37 < ICC > 0.65). Absolute reliability seemed slightly better in the isokinetic protocol than in the field tests, which showed about 12% of test–retest score increase. No significant correlations were found between test scores.

After a familiarisation period for the field tests, the 3 protocols can be used to obtain reliable measures of trunk muscle strength and endurance. Based on the correlation analysis, these measures are not related, which highlights the importance of selecting the most suitable trunk test for each situation.     

多维空间全面分析测量可靠性及其误差成分——多因素方差分析在估价可靠性中的应用

分析比较认为,多因素方差法可从多维空间来分析具有多层面、多种误差的测验观测数,可鉴别出受试者之间(S)、测验之间(D)和测试者之间(T)的误差,以及受试者与各天(次)测验(S·D)之间,受试者与测试者之间(S·T),测试者与各天(次)测验之间(D·T)及受试者、测试者与各天(次)之间(S·D·T)的交互影响(差异);通过误差成分分析,不仅可以求出各误差成分对可靠性影响的程度,而且还可以求出可靠性系数。     

Reliability and validity of depth camera 3D scanning to determine thigh volume

Gross thigh volume is a key anthropometric variable to predict sport performance and health. Currently, it is either estimated by using the frustum method, which is prone to high inter-and intra-observer error, or using medical imaging, which is expensive and time consuming. Depth camera 3D-imaging systems offer a cheap alternative to measure thigh volume but no between-session reliability or comparison to medical imaging has been made. This experiment established between-session reliability and examined agreement with magnetic resonance imaging (MRI). Forty-eight male cyclists had their thigh volume measured by the depth camera system on two occasions to establish between-session reliability. A subset of 32 participants also had lower body MRIs, through which agreement between the depth camera system and MRI was established. The results showed low between-session variability (CV = 1.7%; Absolute Typical Error = 112 cm³) when measuring thigh volume using the depth camera system. The depth camera systematically measured gross thigh volume 32.6cm³ lower than MRI. These results suggest that depth camera 3D-imaging systems are reliable tools for measuring thigh volume and show good agreement with MRI scanners, providing a cheap and time-saving alternative to medical imaging analysis.     

智能变电站分阶段改造方法的研究

21世纪初,智能电网(Smart Grid)概念的提出为全世界电力工业开辟了新的发展空间。智能变电站作为智能电网的物理基础,将贯穿智能电网建设的整个过程。本文对分阶段改造方案进行探讨,并与一般方案进行比较。最后对建设智能变电站带来的经济效益进行了探讨。     

Between-Day Reliability and Usefulness of a Fitness Testing Battery in Youth Sport Athletes: Reference Data for Practitioners

This study aimed to evaluate the between-day reliability and usefulness of a fitness testing battery in a group of youth sport athletes. Fifty-nine youth sport athletes (age = 17.3 ± 0.7 years) undertook a fitness testing battery including the isometric mid-thigh pull, counter-movement jump, 5–40 m sprint splits, and the 5–0-5 change of direction test on two occasions separated by 7 days. Usefulness was assessed by comparing the reliability (typical error) to the smallest worthwhile change. The typical error was 5.5% for isometric mid-thigh pull and 3.8% for counter-movement jump. The typical error values were 2.7, 2.5, 2.2, 2.2, and 1.8% for the 5, 10, 20, 30, and 40 m sprint splits, and 4.1% (left) and 5.4% (right) for the 5–0-5 tests. The smallest worthwhile change ranged from 1.1 to 6.1%. All tests were identified as having “good” or “acceptable” reliability. The isometric mid-thigh pull and counter-movement jump had “good” usefulness, all other tests had “marginal” usefulness.     

苗族城镇中小学学生体表面积调查研究

目的:研究苗族城镇中、小学学生体表面积的生长发育状况,为建立苗族中、小学学生健康指标评价体系提供依据。方法:采用适合中国人的Stevenson标准公式,对苗族城镇中、小学学生体表面积进行研究。结果:1)苗族中、小学学生体表面积值随着年龄增长而增长,其增长速度男、女生均可分为匀速、快速、减缓3个时期;2)男、女生体表面积发育曲线出现双交叉现象,15岁以后表现出显著性差异;3)与汉族学生比较,各年龄组的体表面无显著性差异。结论:苗族学生体表面积的生长发育规律与汉族学生具有一致性,整体生长发育状况与汉族学生处于同一水平,因此,可建立统一的健康指标评价体系标准。     

Development of a Scale to Determine Enrollment Barriers into Allied Health Programs

The purpose of this study was to develop the Scale of Allied Health Education Barriers to identify factors limiting enrollment in college/university allied health education programs. Development of the Scale of Allied Health Education Barriers was conducted through the following four stages: (1) review of literature, (2) focus group studies, (3) pilot testing, and (4) test administration and testing of measurement properties. Research participants (N = 1,044) were students enrolled in allied health and non-allied health education programs. Through conducting both exploratory and confirmatory factor analyses, this study identified five unique factors that are potential barriers to student enrollment in allied health education: Social Influence, Experiential Opportunity, Academic Preparation, Physical Self-Efficacy, and Self-Management. These factors were consistent with the social cognitive theory adopted to guide this study, which posits that personal, environmental, and behavioral factors collectively influence allied health enrollment. Further discussions are made on the practical implications of applying the developed scale to reduce barriers for allied health program recruitments.     

The Reliability and Validity of Protocols for the Assessment of Endurance Sports Performance: An Updated Review

Sports performance testing is one of the most common and important measures used in sport science. Performance testing protocols must have high reliability to ensure any changes are not due to measurement error or inter-individual differences. High validity is also important to ensure test performance reflects true performance. Time-trial protocols commonly have a coefficient of variation (CV) of <5%, however, familiarization, well-trained subjects and/or conducting the trial outdoors in the athlete’s most familiar environment can lead to CVs of < 1%. Long duration time-trials or the inclusion of sprints within a time-trial appears to not negatively influence reliability. Few studies have assessed the validity of endurance performance tests, and as such more research should evaluate different ways of simulating outdoor performances in the laboratory. The use of warm-up, simulation of convection load, and implementation of race specific hydration practices are important considerations for researchers regarding test validity.     

铁人三项自行车-跑换项过程的调整与训练

探讨了造成铁人三项自行车-跑换项过程中运动员常会出现不适感的原因.呼吸肌疲劳、脱水、糖原耗竭和感受器的传导反馈调整落后于身体活动变化,引起生物力学指标的不利改变,使跑的效率下降,可能是造成不适感的主要原因.自行车赛段的骑行位置和最后阶段的蹬车频率会对换项调整产生显著影响,运动员应注意根据自己的特点确定战术.换项过程中运动员身体所承受的特殊变化提示,针对比赛中将会遇到的情况进行专门训练,可能有助于提高运动员的耐受性,加快感受器的调整适应,减小生物力学指标的不利改变,减少运动损伤.     

儿童少年体质场地测试手段的信度研究:系统评价

目的:系统评价现有针对儿童少年人群体质的场地测试手段的信度水平,形成场地测试手段信度水平的综合框架.方法:制定文献检索策略,检索1990年1月～2011年7月公开发表的英文全文文献,根据受试者、重复测试时间间隔、统计方法和研究结果,对纳入文献进行质量评估,根据研究数量和研究结果的一致性确定各场地测试手段信度的证据等级.结果:最终纳入31项高质量研究,其中涉及心肺能力最常见的手段是20 m折返跑、1英里跑/走和Andersen测试;涉及肌肉能力最常见的手段是握力,俯卧撑,纵跳,引体向上,屈臂悬挂,坐位体前屈,背力,屈膝两头起,仰卧起坐和立定跳远;涉及运动能力最常见的测试手段是4×10m往返跑和30m冲刺跑;涉及身体成分最常见的测试手段是人体测量学和通过皮褶厚度推算的体脂百分比.结论:尽管某些场地测试手段的信度水平需要进一步补充研究,基于目前的证据等级提出了针对儿童少年体质场地测试手段信度水平框架.