Quantification of maximal power output in well-trained cyclists

ABSTRACT

This study aimed to compare mechanical variables derived from torque-cadence and power-cadence profiles established from different cycle ergometer modes (isoinertial and isokinetic) and modelling procedures (second- and third-order polynomials), whilst employing a novel method to validate the theoretical maximal power output (P_max). Nineteen well-trained cyclists (n = 12 males) completed two experimental sessions comprising six, 6-s maximal isoinertial or isokinetic cycling sprints. Maximal pedal strokes were extracted to construct power–cadence relationships using second- and third-order polynomials. A 6-s sprint at the optimal cadence (F_opt) or optimal resistance (T_opt) was performed to assess construct validity of P_max. No differences were found in the mechanical parameters when derived from isokinetic (P_max = 1311 ± 415, F_opt = 118 ± 12) or isoinertial modes (P_max = 1320 ± 421, F_opt = 116 ± 19). However, R² improved (P < 0.02) when derived from isoinertial sprints. Third-order polynomial modelling improved goodness of fit values (Standard Error, adjusted R²), but derived similar mechanical parameters. Finally, peak power output during the optimised sprint did not significantly differ from the theoretical P_max in both cycling modes, thus providing construct validity. The most accurate P-C profile can be derived from isoinertial cycling sprints, modelled using third-order polynomial equations.     

我国赛艇运动员中级选材标准调查研究

对全国6个省市赛艇队运动员中级选材标准进行调查,对具体内容进行比较研究,对进一步完善赛艇训练教学大纲中级选材内容提出了建议。     

赛艇测功仪在帆船运动员体能测试中的应用研究

帆船项目与赛艇项目均为有氧项目,对于运动员有氧能力训练都非常重视。目前帆船项目还没有适合自身项目规律的测功仪,帆船的体能测试指标还相对较少,尚未建立体能评价体系。使用赛艇测功仪对国家队帆船470级运动员进行体能测试,验证使用赛艇测功仪作为帆船运动员体能测试手段的可行性,进而分析两个项目对体能需求的相关性,对1998年以来国内外国家队和部分省队的多名优秀女子赛艇公开级与轻量级运动员进行赛艇CONCEPT II测功仪的60min功率测试,并运用文献资料法、系统分析法、实验研究与观察法等将测试结果与赛艇女子运动员进行分析比较。从测试的结果来看,两个项目在有氧能力与无氧能力之间的比例关系非常的接近,说明两者在体能结构上具有一定的相似性。由于赛艇与帆船在体能结构方面的相似性,借助于赛艇项目非常完备的测功仪测试数据,通过统计和分析赛艇体能结构,可促进完成帆船相关评价体系的建立。     

水温对艇速的影响──等功艇速换算

摩擦阻力占整个阻力的绝大部分,摩擦阻力主要受船艇的表面面积、水的密度、水的粘性系数等的影响,这些同水温有密切的关系。     

Bivariate functional principal components analysis: considerations for use with multivariate movement signatures in sports biomechanics

Sporting performance is often investigated through graphical observation of key technical variables that are representative of whole movements. The presence of differences between athletes in such variables has led to terms such as movement signatures being used. These signatures can be multivariate (multiple time-series observed concurrently), and also be composed of variables measured relative to different scales. Analytical techniques from areas of statistics such as Functional Data Analysis (FDA) present a practical alternative for analysing multivariate signatures. When applied to concurrent bivariate time-series multivariate functional principal components analysis (referred to as bivariate fPCA or bfPCA in this paper) has demonstrated preliminary application in biomechanical contexts. Despite this, given the infancy of bfPCA in sports biomechanics there are still necessary considerations for its use with non-conventional or complex bivariate structures. This paper focuses on the application of bfPCA to the force-angle graph in on-water rowing, which is a bivariate structure composed of variables with different units. A normalisation approach is proposed to investigate and standardise differences in variability between the two variables. The results of bfPCA applied to the non-normalised data and normalised data are then compared. Considerations and recommendations for the application of bfPCA in this context are also provided.     

对赛艇低桨频训练的探讨

阐述低桨频训练的理论依据,列举广东赛艇队通过低桨频训练产生良好效果的实例,提出低桨频训练应该注意的事项。     

赛艇多参数遥测分析系统的研制

研究目的是研制一套快速反馈系统,用于测试和分析赛艇技术的生物力学参数。本系统于1989年研制成功,它由无线电发射机、无线电接收机、传感器、同步器及其相应软件组成。系统有6个通道,用以同步测量:作用于桨环上的力,桨在水平面内的角位移,艇加速度,运动心率。系统的采样频率为50Hz,有效遥测距离大干500米。系统软件能在几分钟内计算出50多个技术参数,给出统计结果,并能根据运动员不同的技术模式对桨入水角进行优化。     

女子2000米赛艇运动员不同训练周期中有氧和无氧代谢能力变化

本文观察了16名女子赛艇运动员30周训练期间有氧和无氧代谢运动能力的变化。前13周以力量训练为主,后17周以专项训练为主。观察发现过多力量训练无助于有氧能力发展,在专项训练期,应保持足够强度才能在发展有氧能力的同时提高最大乳酸值。     

3种自行车功率计无氧功率测试结果的比较

采用 Monark 834,Monark 839E,SRM3种自行车功率计对8名优秀男子自行车运动员进行30s Wingate 元氧功率测试(WAT),对测试结果进行比较,分析3种功率计测定参数的异同与自行车实际运动方式的差异。结果表明:Monark834进行 Wingate 测试和自行车运动实践不尽相符。Monark 839E 可以比较精确的反映受试者的起动能力。Monark 834和 Monark839E 进行 WAT 测试时,其预定负荷受到一定的限制。SRM 测试指标的内容和精度较Monark834、Monark 839E要高。从模拟自行车运动实际状况来看,SRM 是更适合自行车运动员测试的专业工具。     

气功对女子赛艇运动员赛前的影响

以气功为赛前疲劳的调节方法,对武汉体育学院女子赛艇轻量级运动员,于1998年全国青年赛艇锦标赛前进行了半个月的疲劳恢复,研究中测试了练功前后的血红蛋白、运动成绩等.结果表明:气功有助于赛艇运动员赛前身体机能的恢复并可提高人体的运动能力.