背景:概念2(C2)划船测功机在全球范围内用于基于家庭的训练,官方比赛,以及体育和科学方面的绩效评估。先前的研究报告了机械动力输出的完全低估与不清楚定义的中风变异性正相关。这项研究的目的是量化C2的准确性,同时通过使用用于空气制动划船测功机的测试台来控制划船行程的潜在影响变量,从而排除生物变异性。
方法:采用了一种用于划船测力计的独特电动试验台。准确性被评估为在稳定期间C2和参考系统之间的机械功率输出差异(即,行程功率在一系列50个空间内的最小变化,无笔划)和不稳定的模拟划船(即,测量系列期间的持续变化),同时操纵冲程变量形状,力,或费率。
结果:在稳定的模拟划船过程中,C2和参考系统之间的差异在2.9-4.3%之间。差异不受中风形状的影响(P=0.153),但按卒中发生率为22-28min-1(P<0.001)。在不稳定的模拟划船过程中,随着行程力和速度的变化,2.5-3.9%的平均差异与稳定模拟划船期间相似,但随机误差增加了18倍。C2低估了前五个冲程的机械动力输出10-70%。他们的排除将平均差异降低到0.2-1.9%。
结论:由于对起始行程的极大低估,C2的标称精度取决于所考虑的笔划的总数。范围为0.2-1.9%,一旦飞轮被充分加速。划船不均匀会增加不准确性,但中风的形状有边际影响。因此,划船者应尽可能均匀地划船,并更喜欢更高的划水率以优化C2读数。我们建议使用外部参考系统进行科学和高性能评估,特别是对于短测试设计,其中的开始行程将产生重大影响。
BACKGROUND: The Concept 2 (C2) rowing ergometer is used worldwide for home-based training, official competitions, and performance assessment in sports and science. Previous studies reported a disparate underestimation of mechanical power output positively related to an unclearly defined stroke variability. The aim of this study was to quantify the accuracy of the C2 while controlling for the potentially influencing variables of the rowing stroke by using a test rig for air-braked rowing ergometers and thus excluding biological variability.
METHODS: A unique motorized test rig for rowing ergometers was employed. Accuracy was assessed as the difference in mechanical power output between C2 and a reference system during steady (i.e., minimal variations of stroke power within a series of 50 spacemark, no -strokes) and unsteady simulated rowing (i.e., persistent variations during measurement series) while manipulating the stroke variables shape, force, or rate.
RESULTS: During steady simulated rowing, differences between C2 and the reference system ranged 2.9-4.3%. Differences were not significantly affected by stroke shapes (P = 0.153), but by stroke rates ranging 22-28 min-1 (P < 0.001). During unsteady simulated rowing with alterations of stroke force and rate, mean differences of 2.5-3.9% were similar as during steady simulated rowing, but the random error increased up to 18-fold. C2 underestimated mechanical power output of the first five strokes by 10-70%. Their exclusion reduced mean differences to 0.2-1.9%.
CONCLUSIONS: Due to the enormous underestimation of the start strokes, the nominal accuracy of the C2 depends on the total number of strokes considered. It ranges 0.2-1.9%, once the flywheel has been sufficiently accelerated. Inaccuracy increases with uneven rowing, but the stroke shape has a marginal impact. Hence, rowers should row as even as possible and prefer higher stroke rates to optimize C2 readings. We recommend external reference systems for scientific and high-performance assessments, especially for short tests designs where the start strokes will have a major impact.