Bicycle rider control skills: expertise and assessment     

Borut Fonda  Nejc Sarabon 《Journal of sports sciences》2017,35(14):1383-1391

Abstract

Research on how human balance and control bicycles are inconclusive, largely due to the small number of participants in the previous studies. Therefore, the aim of this study was to test the hypotheses that 1) cycling lateral deviation amplitude will reliably show differences between more and less experienced cyclists and 2) more experienced will exhibit slower and smaller steering motions compared to the less experienced cyclists. Twenty-eight experienced and inexperienced cyclists rode a bicycle in a straight line. Lateral deviation, steering and roll were measured. Intersession reliability of the deviation was high with Cronbach’s alpha values higher than 0.75. The amplitude, variability and rate of steering and roll parameters showed statistically significant differences between the groups. The test used in this study is sensitive to detect differences between more and less experienced cyclists and can be used for further research that aims to test the effect of a specific intervention addressing rider control. We also showed that steering and roll angle, which were described before as two of the main motor control actions in bicycle control, differ in the variability, amplitude and rate between more and less experienced cyclists. The results of the present study have practical implications for improving bicycle rider control and increasing the safety of cyclists.  相似文献   

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

Barney Wainwright  Carlton Brian Cooke  John Paul O’Hara 《Journal of sports sciences》2017,35(14):1451-1458

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.  相似文献   

不同强度骑车和跑步的能量消耗与底物代谢特征研究   总被引：4，自引：2，他引：2  

张勇  王恬 《中国体育科技》2009,45(1)

目的:研究比较不同强度骑车和跑步的能量消耗与底物代谢特征。方法:10名普通女大学生分别以45%、55%、65%、75%.VO2max强度进行骑车和跑步运动,采用气体代谢法测定机体的能量代谢状况。结果:1)骑车时,脂肪的消耗量和供能量在55%V.O2max强度达到最高,分别为4.26mg/min/kg和38.38cal/min/kg。跑步运动时,脂肪的消耗量和供能量在55%V.O2max强度达到最高,分别为6.41mg/min/kg和57.65cal/min/kg;2)在45%、55%、65%、75%V.O2max强度,跑步脂肪氧化量、总供能量、脂肪供能比例均高于骑车;而跑步的糖消耗量和呼吸交换率低于骑车。结论:1)无论骑车还是跑步,在45%、55%、65%、75%V.O2max4个运动强度中,55%V.O2max强度运动时的脂肪的氧化和供能量最大;2)在相同运动强度(%V.O2max)下,跑步总能量消耗、脂肪消耗和脂肪供能比例高于骑车,糖的消耗低于骑车。  相似文献   

Development and field validation of an omni-domain power-duration model     

Michael J. Puchowicz  Jonathan Baker 《Journal of sports sciences》2020,38(7):801-813

ABSTRACT

Purpose: To validate and compare a novel model based on the critical power (CP) concept that describes the entire domain of maximal mean power (MMP) data from cyclists.

Methods: An omni-domain power-duration (OmPD) model was derived whereby the rate of W? expenditure is bound by maximum sprint power and the power at prolonged durations declines from CP log-linearly. The three-parameter CP (3CP) and exponential (Exp) models were likewise extended with the log-linear decay function (Om3CP and OmExp). Each model bounds W? using a different nonconstant function, W?eff (effective W?). Models were fit to MMP data from nine cyclists who also completed four time-trials (TTs).

Results: The OmPD and Om3CP residuals (4 ± 1%) were smaller than the OmExp residuals (6 ± 2%; P < 0.001). W?eff predicted by the OmPD model was stable between 120–1,800 s, whereas it varied for the Om3CP and OmExp models. TT prediction errors were not different between models (7 ± 5%, 8 ± 5%, 7 ± 6%; P = 0.914).

Conclusion: The OmPD offers similar or superior goodness-of-fit and better theoretical properties compared to the other models, such that it best extends the CP concept to short-sprint and prolonged-endurance performance.  相似文献   

场地自行车在直弯道之间的速度波动研究   总被引：6，自引：4，他引：2  

张百鸣  沈金康  朱柏强 《体育科研》2005,26(1):57-60

用5台德国产自行车数据收集分析系统(SRM自行车仪),收集、处理在南京、深圳、昆明等场地自行车训练和比赛的生物力学数据,按照不同场地,不同骑行速度计算人车系统在进出直弯道时平均速度和最大速度的变化。结果表明:速度波动与场地半径有显著性关系。当自行车从直道进入弯道时速度增加,而自行车从弯道进入直道时速度减小。250m场地上的速度波动比333.3m场地更大。速度波动与运动员骑行速度没有显著性关系。  相似文献   

辽宁省城市循环经济发展水平综合评价     

冯艳 《锦州师范学院学报(哲学社会科学版)》2006,28(3):91-93

我国的许多城市已经面临越来越严重的资源、环境和发展的困境,通过循环经济建设可以改变城市的发展模式,提高城市的可持续发展能力.对循环经济的发展状况进行评价是发展循环经济的一个必要步骤,在充分考虑经济增长、社会进步与资源的有效利用、环境保护之间相互制约关系的基础上,建立循环经济评价指标体系,并对辽宁省各主要城市循环经济发展水平进行排序.  相似文献   

“互联网+体育”国际体育信息采集的研究--以国际场地自行车项目为例     

朱建伟  朱天然 《冰雪运动》2016,(4):27-33

对国际体育信息的采集、归纳、整理、分析,对把握国际体育发展的趋势,与世界保持同步具有重要的意义。国际奥委会、各种世界体育协会（联盟）的官方网站,世界著名媒体的新闻网站,自媒体是国际体育信息收集的主要网络渠道。筛选网络信息的原则是,泛览精收原则,有效确认原则。网络信息收集的注意事项是,尽量注明信息源出处,尊重作者版权;内容以专业人士学习、参考为主。信息采集的内容以各国比赛成绩资料的收集,国际比赛图像信息资料的收集,国际体育赛事的专项新闻信息收集为主。通过信息了解国际自盟（ UCI）项目设置的竞赛规则,了解国际规则变化及对手情况,掌握自行车专项器材、研究方法、手段的改进与创新等。  相似文献   

Agreement of Power Measures between Garmin Vector and SRM Cycle Power Meters     

Andrew R. Novak  Benjamin J. Dascombe 《Measurement in physical education and exercise science》2016,20(3):167-172

This study aimed to determine if the Garmin Vector (Schaffhausen, Switzerland) power meter produced acceptable measures when compared with the Schoberer Rad Messetechnik (SRM; Julich, Germany) power meter across a range of high-intensity efforts. Twenty-one well-trained cyclists completed power profiles (seven maximal mean efforts between 5 and 600 s) using Vector and SRM power meters. Data were compared using assessments of heteroscedasticity, t tests, linear regression, and typical error of estimate (TEE). The data were heteroscedastic, whereby the Vector pedals increasingly overestimated values at higher power outputs; however, t tests did not identify any significant differences between power meters (p > .05). Using linear regression, Vector data were fit to an SRM equivalent (slope = .99; intercept = ?9.87) and TEE produced by this equation was 3.3% (3.0%–3.8%). While the data shows slight heteroscedasticity due to differing strain-gauge placement and resultant torque measurement variance, the Vector appears acceptable for measures of power output across various cycling efforts.  相似文献   

浅谈C语言的循环结构及循环优化     

张丽姝 《天津职业院校联合学报》2001,3(4):77-82

C语言是结构化的程序设计语言,适合于编写系统软件,同时也适合作为程序设计教学语言.提高程序的执行效率是编程者所追求的目标,对循环做较深入的优化可以大幅度地提高程序的效率.  相似文献   

最大摄氧量间接测定方法PWC170法与两步台阶实验法比较研究     

王维军 《喀什师范学院学报》2007,28(6):77-79

采用文献资料法、对比法和数据统计法,对最大摄氧量及其间接测定方法进行了研究分析,初步总结出最大摄氧量受遗传、性别、年龄、环境、营养饮食状况、生活习惯和训练等因素的影响.运动时对心肺功能的测定是科学训练的一个重要方面.而评价心肺功能的最佳指标是最大摄氧量,最大摄氧量是反映有氧工作能力的有效指标之一.通过对最大摄氧量间接测定方法PWC170法与两步台阶实验法比较研究,有利于从测试的精确度、测试的简易性、测试的效率、测试费用及训练评价效果方面提供更好的理论依据.  相似文献