上海女子自行车运动员冲刺骑行中的下肢运动学评价          下载免费PDF全文

何俊良  许以诚  马国强 《体育科研》2018,(2):87-90

对女子短距离自行车运动员45 s全力冲刺骑行进行下肢运动学分析,探讨不同水平运动员速度能力的特点,筛选可评价下肢踏蹬技术的运动学指标。使用三维红外运动捕捉系统及SRM自行车测功仪,采集上海自行车队4名女子短距离运动员场地车滚筒练习台上45 s全力冲刺骑行中的下肢运动学参数和踏频。结果表明,钟××速度能力较好,45 s全力冲刺骑行各阶段平均速度较高,但下肢踏蹬"圆滑度"还需进一步提高;顾××和姚××后程速度下降明显,速度耐力明显不足。在全力冲刺骑行后期,运动水平较高的运动员（钟××）踝关节活动度下降明显小于运动水平较低的运动员（顾××和姚××）,提示踝关节活动度下降是影响自行车短距离项目运动员速度耐力的因素之一。  相似文献   

Physical characteristics and resistance parameters of typical urban cyclists     

Simone Tengattini 《Journal of sports sciences》2018,36(20):2383-2391

This study investigates the rolling and drag resistance parameters and bicycle and cargo masses of typical urban cyclists. These factors are important for modelling of cyclist speed, power and energy expenditure, with applications including exercise performance, health and safety assessments and transportation network analysis. However, representative values for diverse urban travellers have not been established. Resistance parameters were measured utilizing a field coast-down test for 557 intercepted cyclists in Vancouver, Canada. Masses were also measured, along with other bicycle attributes such as tire pressure and size. The average (standard deviation) of coefficient of rolling resistance, effective frontal area, bicycle plus cargo mass, and bicycle-only mass were 0.0077 (0.0036), 0.559 (0.170) m², 18.3 (4.1) kg, and 13.7 (3.3) kg, respectively. The range of measured values is wider and higher than suggested in existing literature, which focusses on sport cyclists. Significant correlations are identified between resistance parameters and rider and bicycle attributes, indicating higher resistance parameters for less sport-oriented cyclists. The findings of this study are important for appropriately characterising the full range of urban cyclists, including commuters and casual riders.  相似文献   

The multi-stage fitness test as a predictor of endurance fitness in wheelchair athletes     

Victoria L. Goosey-Tolfrey  Keith Tolfrey 《Journal of sports sciences》2013,31(5):511-517

Abstract

The aims of this study were two-fold: (1) to consider the criterion-related validity of the multi-stage fitness test (MSFT) by comparing the predicted maximal oxygen uptake ([Vdot]O_2max) and distance travelled with peak oxygen uptake ([Vdot]O_2peak) measured using a wheelchair ergometer (n = 24); and (2) to assess the reliability of the MSFT in a sub-sample of wheelchair athletes (n = 10) measured on two occasions. Twenty-four trained male wheelchair basketball players (mean age 29 years, s = 6) took part in the study. All participants performed a continuous incremental wheelchair ergometer test to volitional exhaustion to determine [Vdot]O_2peak, and the MSFT on an indoor wooden basketball court. Mean ergometer [Vdot]O_2peak was 2.66 litres · min^?1 (s = 0.49) and peak heart rate was 188 beats · min^?1 (s = 10). The group mean MSFT distance travelled was 2056 m (s = 272) and mean peak heart rate was 186 beats · min^?1 (s = 11). Low to moderate correlations (ρ = 0.39 to 0.58; 95% confidence interval [CI]: ?0.02 to 0.69 and 0.23 to 0.80) were found between distance travelled in the MSFT and different expressions of wheelchair ergometer [Vdot]O_2peak. There was a mean bias of ?1.9 beats · min^?1 (95% CI: ?5.9 to 2.0) and standard error of measurement of 6.6 beats · min^?1 (95% CI: 5.4 to 8.8) between the ergometer and MSFT peak heart rates. A similar comparison of ergometer and predicted MSFT [Vdot]O_2peak values revealed a large mean systematic bias of 15.3 ml · kg^?1 · min^?1 (95% CI: 13.2 to 17.4) and standard error of measurement of 3.5 ml · kg^?1 · min^?1 (95% CI: 2.8 to 4.6). Small standard errors of measurement for MSFT distance travelled (86 m; 95% CI: 59 to 157) and MSFT peak heart rate (2.4 beats · min^?1; 95% CI: 1.7 to 4.5) suggest that these variables can be measured reliably. The results suggest that the multi-stage fitness test provides reliable data with this population, but does not fully reflect the aerobic capacity of wheelchair athletes directly.  相似文献   

Reliability and discriminative ability of a modified Wingate rowing test in 12- to 18-year-old rowers     

Pavle Mikulic  Davor Emersic  Goran Markovic 《Journal of sports sciences》2013,31(13):1409-1414

Abstract

We evaluated (1) the test–retest reliability of the Wingate test conducted on a rowing ergometer, and (2) the sensitivity of this test in determining the differences in performance attained by 12- to 18-year-old rowers. Altogether, 297 male rowers aged 12.0–18.9 years (mean ± s: 14.8 ± 1.7) completed a maximal 30-s test on a rowing ergometer, and 80 rowers representing all age groups were retested after 5–7 days. No change was evident in participants' performance in terms of mean power output (P = 0.726; Cohen's d = 0.04), maximal power output (P = 0.567; Cohen's d = 0.06), and minimum power output (P = 0.318; Cohen's d = 0.11) in the second test. The intra-class correlation coefficients were high (≥0.973) and coefficients of variation were low (≤7.3%). A series of analyses of variance were used to compare the performances among 12- to 18-year-old rowers, and age-related increases in performance were evident (P < 0.001; Cohen's d = 1.91–1.96). The age-related increases in performance were similar, although reduced, when the effects of body mass were partitioned out when using analysis of covariance (P < 0.001; Cohen's d = 0.82–0.85). The results suggest that: (1) the described test is reliable and can be used for maximal-intensity exercise assessment in youth rowing, and (2) it discriminates performance among 12- to-18-year-old rowers.  相似文献   

不同强度自行车运动对普通男大学生锻炼者能量消耗的影响研究     

王世涛 《体育科技》2013,(5):60-61,66

目的：探讨不同强度自行车运动对普通男大学生锻炼者能量消耗的影响.方法：利用CORTEX3B便携式心肺功能仪依次测出32名男大学生在4级不同负荷阶段的能量消耗相关指标,并加以统计分析.结论：从能量消耗角度看,18km/-77r/min负荷强度下的能量消耗最为平均,从长时间自行车运动供能角度来说对男大学生健身有积极作用.  相似文献   

Relative shank to thigh length is associated with different mechanisms of power production during elite male ergometer rowing     

Andrew J. Greene  Michael H. Dickson  Floren Colloud  Richard M. Smith 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):302-317

The effect of anthropometric differences in shank to thigh length ratio upon timing and magnitude of joint power production during the drive phase of the rowing stroke was investigated in 14 elite male rowers. Rowers were tested on the RowPerfect ergometer which was instrumented at the handle and foot stretcher to measure force generation, and a nine segment inverse dynamics model used to calculate the rower's joint and overall power production. Rowers were divided into two groups according to relative shank thigh ratio. Time to half lumbar power generation was significantly earlier in shorter shank rowers (p = 0.028) compared to longer shank rowers, who showed no lumbar power generation during the same period of the drive phase. Rowers with a relatively shorter shank demonstrated earlier lumbar power generation during the drive phase resulting from restricted rotation of the pelvic segment requiring increased lumbar extension in these rowers. Earlier lumbar power generation and extension did not appear to directly affect performance measures of the short shank group, and so can be attributed to a technical adaptation developed to maximise rowing performance.  相似文献   

人体运动能耗分配关系的实验研究     

石新燕  李美霞 《西安体育学院学报》2012,29(4):492-496

目的估测人体运动过程中参与工作的各子系统的能耗,建立较为精细的人体运动能耗分配关系。方法研究对13名大学生(男性)进行了功率自行车设定负荷下的运动代谢实验、多域多维心功能检测以及动作技术影像拍摄和解析,并对人体运动能量系统和做功进行了建模分析。结果受试者在给定的相同负荷功率下以不同转速蹬功率自行车时的运动能耗差异显著;总搏功两两之间均无显著性差异(P>0.05);无用功两两之间比较差异显著(P<0.001)。结论心脏做功仅与负荷量(输出功率)有关,而在给定负荷情况下心脏做功与速度大小无关;运动参数的改变显著影响运动无用功,也影响总能量消耗;在中等强度踏蹬自行车运动中,呼吸系统、循环系统、骨骼肌系统分别消耗总能量的11.02%,52.86%,5.36%;剩余30%左右的能量为对外做功和移动肢体做功(分别为25.72%和5.04%)。研究还为估测运动能耗在不同系统间的分配关系提供了一种可行方法。  相似文献   

电动自行车后轮碟刹安装设计     

章文英  李银海  王瑞敏 《金华职业技术学院学报》2009,9(3):34-36

随着电动自行车设计的最高车速的提高,对刹车系统提出更高的要求,为此提出电动车实现后轮碟刹的设想。经对后轮碟刹实现的可能性及后轮碟刹装置安装方法的分析,结果：后轮具有安装碟刹装置的空间。并可以通过改造链条齿轮或电机壳的方法来实现后轮碟刹装置的安装。  相似文献   

模拟高原环境下自行车驴友急性骑行能力研究*     

蓝道忠  翁锡全  胡婧  周柏星  黄丽英 《广州体育学院学报》2015,35(3):86-89

目的:探讨模拟高原环境下急性骑行对自行车驴友运动能力的影响。方法:受试对象为7名华南农业大学一年级男性学生,平均年龄19.80±0.83岁,为自行车驴友,没有高原旅行经历。受试者分别在常氧环境和模拟常压低氧环境(氧含量16.8%)进行踏功率自行车运动,强度从50W(50rpm)开始,每3min递增50W至250W,然后要求受试者以最大能力运动至力竭,测试指标包括运动前、每级负荷后即刻和运动后心率、RPE、血乳酸及力竭时间。结果:两种环境下的心率与RPE均随着运动强度的增大而呈上升趋势,在模拟高原环境下从150W至250W以及力竭后心率上升幅度高于常氧,而RPE从150W后至运动结束时也高于常氧环境,但均无统计学差异(P>0.05),并且力竭时间非常显著性缩短(P<0.01)。结论:高原环境下自行车驴友骑行能力有一定下降,提示自行车驴友初入高原时要适当降低骑行强度及作适当的休息。  相似文献   

小轮车竞速运动的特点及发展对策     

庞建超 《军事体育进修学院学报》2012,31(2):73-74,86

简要分析小轮车竞速项目的特点和技术要求,介绍了小轮车运动的发展历史和现状,并针对我国小轮车运动发展晚等现实,从普及该项运动路径、改进训练方法、提升实战能力和壮大人才队伍等方面提出指导性发展对策。  相似文献