自行车世界杯2004年第五站男子4公里个人追逐赛初步研究     

李红 《首都体育学院学报》2004,16(2):86-88

本文根据2004年自行车世界杯第五站(云南站)男子4公里个人追逐赛项目现场统计数据用统计学方法进行了统计计算,对比赛的状况作了初步的研究。结论认为,自行车场地男子4公里个人追逐赛全程的各环节中,速度能力是最关键的一环。该项目虽然是中距离的项目,但速度是关键。  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   

Respiratory frequency is strongly associated with perceived exertion during time trials of different duration     

Andrea Nicolò  Samuele M. Marcora 《Journal of sports sciences》2016,34(13):1199-1206

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Performance differences when using 26- and 29-inch-wheel bikes in Swiss National Team cross-country mountain bikers     

Thomas Steiner  Beat Müller  Thomas Maier  Jon Peter Wehrlin 《Journal of sports sciences》2016,34(15):1438-1444

The purpose of this study was to analyse the effect of bike type – the 26-inch-wheel bike (26“ bike) and the 29-inch-wheel bike (29“ bike) – on performance in elite mountain bikers. Ten Swiss National Team athletes (seven males, three females) completed six trials with individual start on a simulated cross-country course with 35 min of active recovery between trials (three trials on a 26“ bike and three trials on a 29“ bike, alternate order, randomised start-bike). The course consisted of two separate sections expected to favour either the 29“ bike (section A) or the 26“ bike (section B). For each trial performance, power output, cadence and heart rate were recorded and athletes’ experiences were documented. Mean overall performance (time: 304 ± 27 s vs. 311 ± 29 s; P < 0.01) and performance in sections A (P < 0.001) and B (P < 0.05) were better when using the 29“ bike. No significant differences were observed for power output, cadence or heart rate. Athletes rated the 29“ bike as better for performance in general, passing obstacles and traction. The 29“ bike supports superior performance for elite mountain bikers, even on sections supposed to favour the 26“ bike.  相似文献   

Effects of power variation on cycle performance during simulated hilly time-trials     

Marc S. Wells 《European Journal of Sport Science》2016,16(8):912-918

It has previously been shown that cyclists are unable to maintain a constant power output during cycle time-trials on hilly courses. The purpose of the present study is therefore to quantify these effects of power variation using a mathematical model of cycling performance. A hypothetical cyclist (body mass: 70?kg, bicycle mass: 10?kg) was studied using a mathematical model of cycling, which included the effects of acceleration. Performance was modelled over three hypothetical 40-km courses, comprising repeated 2.5-km sections of uphill and downhill with gradients of 1%, 3%, and 6%, respectively. Amplitude (5–15%) and distance (0.31–20.00?km) of variation were modelled over a range of mean power outputs (200–600?W) and compared to sustaining a constant power. Power variation was typically detrimental to performance; these effects were augmented as the amplitude of variation and severity of gradient increased. Varying power every 1.25?km was most detrimental to performance; at a mean power of 200?W, performance was impaired by 43.90?s (±15% variation, 6% gradient). However at the steepest gradients, the effect of power variation was relatively independent of the distance of variation. In contrast, varying power in parallel with changes in gradient improved performance by 188.89?s (±15% variation, 6% gradient) at 200?W. The present data demonstrate that during hilly time-trials, power variation that does not occur in parallel with changes in gradient is detrimental to performance, especially at steeper gradients. These adverse effects are substantially larger than those previously observed during flat, windless time-trials.  相似文献   

降低循环水场循环水浊度新方法探究   总被引：1，自引：0，他引：1  

吕雯静  陈贺 《兰州石化职业技术学院学报》2011,11(3):13-15

针对循环水浊度偏高问题,分析造成悬浮物、浊度升高的原因,通过增加隔油池排泥反洗实验,探究降低循环水浊度的新方法,评价排泥反洗中试装置中,浅层压力式过滤罐与滤池降低浊度的效果对比,在加药和不加药两种情况下,浊度和去除率的情况。  相似文献   

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   

女子自行车运动训练原则与方法的研究     

关北光 《中国体育科技》1998,(4)

本文就河南女子自行车队的成功经验,对女子自行车运动的训练原则与方法进行了探讨。  相似文献   

不同专项训练对男子短距离自行车运动员无氧能力的影响   总被引：2，自引：2，他引：0  

马国强  李之俊  刘茂  严金慧 《体育科研》2007,28(1):71-74

分析两个阶段不同侧重的专项训练前后男子短距离自行车运动员无氧功和专项成绩的变化,探讨不同专项训练对无氧能力的影响,为合理安排训练计划、评价训练效果提供依据。在冬训期间,对运动员的15s、30s无氧功和场地专项成绩测试结果显示,专项力量训练提高了运动员的磷酸原供能能力,但8周训练时间过长,造成了专项频率水平的降低,影响了成绩。专项频率训练虽然使无氧能力小幅下降,但对运动员骑行频率的改善从整体上提高了短距离运动员的专项成绩。在训练计划的制定中,应合理安排各种专项训练手段的比例。  相似文献   

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   总被引：6，自引：6，他引：0  

李之俊  马国强  苟波 《体育科研》2007,28(4):55-58

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。  相似文献