Treff Gunnar, Mentz Lennart, Mayer Benjamin, Winkert Kay, Engleder Thomas, Steinacker Jürgen M
Division of Sports- and Rehabilitation Medicine, Ulm University, Ulm, Germany.
University Institute of Sports Medicine, Prevention and Rehabilitation, Paracelsus Medical University, Salzburg, Austria.
Front Sports Act Living. 2022 Jan 25;3:801617. doi: 10.3389/fspor.2021.801617. eCollection 2021.
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.
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.
During steady simulated rowing, differences between C2 and the reference system ranged 2.9-4.3%. Differences were not significantly affected by stroke shapes ( = 0.153), but by stroke rates ranging 22-28 min ( < 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%.
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.
Concept 2（C2）划船测功仪在全球范围内用于居家训练、官方比赛以及体育和科学领域的性能评估。先前的研究报告称，与定义不明确的划桨变异性呈正相关的机械功率输出存在不同程度的低估。本研究的目的是通过使用空气制动划船测功仪的测试装置来控制划船划桨的潜在影响变量，从而排除生物变异性，以量化C2的准确性。
采用了一种独特的划船测功仪电动测试装置。在稳定（即50次划桨内划桨功率变化最小，无空划）和不稳定模拟划船（即测量过程中持续变化）期间，通过操纵划桨变量形状、力量或速率，将准确性评估为C2与参考系统之间机械功率输出的差异。
在稳定模拟划船期间，C2与参考系统之间的差异在2.9%-4.3%之间。差异不受划桨形状的显著影响（P=0.153），但受每分钟22-28次划桨速率的影响（P<0.001）。在划桨力量和速率发生变化的不稳定模拟划船期间，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将前五次划桨的机械功率输出低估了10%-70%。排除这些划桨后，平均差异降至0.2%-1.9%。
由于起始划桨的巨大低估，C2的标称准确性取决于所考虑的划桨总数。一旦飞轮充分加速，其范围为0.2%-1.9%。划船不均匀时误差会增加，但划桨形状的影响较小。因此，划船者应尽可能均匀地划桨，并选择较高的划桨速率以优化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，特别是对于起始划桨将产生重大影响的短测试设计。
