Introduction: Power meter is a useful tool for monitoring cyclists’ training and race performance. However, limited data are available regarding BMX racing power output. The aim of this study was to characterise the power production of BMX riders and investigate its potential role on race performance.
Methods: Fourteen male riders (age: 20.3 ± 1.5 years, height: 1.75 ± 0.05 m, mass: 70.2 ± 6.4 kg) participated in this study. The tests consist of performing two races apart from 15-min recovery. SRM power meter was used to record power and cadence. Cyclists’ fastest race was used for the data analysis. Heart rate was recorded at 1-s intervals using a Garmin HR chest strap. Lap time was recorded using four pairs of photocells positioned at the start gate, bottom of the start ramp, end of first corner (time cornering), and on the finish line.
Results: There was a large correlation between race time and relative peak power (r = − 0.68, p < 0.01) as well as average power with zero value excluded (r = − 0.52, p < 0.01). Race time was also significantly associated with time cornering (r = 0.58, p < 0.01). Peak power (1288.7 ± 62.6 W) was reached in the first 2.34 second of the race. With zero values included, the average power was 355.8 ± 25.4 W, which was about 28% of the peak power, compared to 62% when zero values were excluded (795.6 ± 63.5 W).
Conclusion: The post-race analysis of the power data might help the cyclists recognizing the need to apply certain strategies on pedalling rates and power production in certain portions of the BMX track, specially, at the start and around the first corner. BMX coaches must consider designing training programs based on the race intensity and power output zones.

Keywords: BMX race, cadence, heart rate, power binning


中文翻译：

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野战自行车电动叉车（BMX）的功率分析

简介：功率计是监测骑自行车者的训练和比赛表现的有用工具。但是，有关BMX赛车动力输出的数据有限。这项研究的目的是表征BMX赛车手的动力输出，并研究其在比赛表现中的潜在作用。
方法：十四名男性骑手（年龄：20.3±1.5岁，身高：1.75±0.05 m，体重：70.2±6.4 kg）参加了这项研究。测试包括进行15分钟恢复以外的两次比赛。SRM功率计用于记录功率和节奏。骑自行车者最快的比赛用于数据分析。使用Garmin HR胸带以1秒的间隔记录心率。使用位于开始门，开始斜坡的底部，第一个拐角（时间拐弯）的终点和终点线上的四对光电管记录间隔时间。
结果：竞赛时间和相对峰值功率（r = − 0.68，p <0.01）与排除零值的平均功率（r = − 0.52，p）之间存在很大的相关性<0.01）。比赛时间也与转弯时间显着相关（r = 0.58，p <0.01）。在比赛的前2.34秒达到了峰值功率（1288.7±62.6 W）。包括零值时，平均功率为355.8±25.4 W，约为峰值功率的28％，而排除零值时的平均功率为62％（795.6±63.5 W）。
结论：功率数据的赛后分析可能有助于骑自行车的人认识到有必要在BMX轨道的某些部分，特别是在起点和第一个拐角处，对踏板速度和功率产生采取某些策略。BMX教练必须考虑根据比赛强度和功率输出区域设计训练计划。

关键字： BMX种族，节奏，心率，功率分级