Bertucci W, Duc S, Villerius V, Pernin J N, Grappe F
Laboratoire de Mécanique Appliquée (U.M.R. C.N.R.S. 6604), Université de Franche Comté, Besançon, France.
Int J Sports Med. 2005 Dec;26(10):868-73. doi: 10.1055/s-2005-837463.
The SRM power measuring crank system is nowadays a popular device for cycling power output (PO) measurements in the field and in laboratories. The PowerTap (CycleOps, Madison, USA) is a more recent and less well-known device that allows mobile PO measurements of cycling via the rear wheel hub. The aim of this study is to test the validity and reliability of the PowerTap by comparing it with the most accurate (i.e. the scientific model) of the SRM system. The validity of the PowerTap is tested during i) sub-maximal incremental intensities (ranging from 100 to 420 W) on a treadmill with different pedalling cadences (45 to 120 rpm) and cycling positions (standing and seated) on different grades, ii) a continuous sub-maximal intensity lasting 30 min, iii) a maximal intensity (8-s sprint), and iiii) real road cycling. The reliability is assessed by repeating ten times the sub-maximal incremental and continuous tests. The results show a good validity of the PowerTap during sub-maximal intensities between 100 and 450 W (mean PO difference -1.2 +/- 1.3 %) when it is compared to the scientific SRM model, but less validity for the maximal PO during sprint exercise, where the validity appears to depend on the gear ratio. The reliability of the PowerTap during the sub-maximal intensities is similar to the scientific SRM model (the coefficient of variation is respectively 0.9 to 2.9 % and 0.7 to 2.1 % for PowerTap and SRM). The PowerTap must be considered as a suitable device for PO measurements during sub-maximal real road cycling and in sub-maximal laboratory tests.
如今，SRM功率测量曲柄系统是一种在野外和实验室中用于测量骑行功率输出（PO）的常用设备。PowerTap（美国麦迪逊CycleOps公司）是一种较新且不太知名的设备，它可以通过后轮花鼓进行骑行的移动PO测量。本研究的目的是通过将PowerTap与SRM系统中最精确的（即科学模型）进行比较，来测试其有效性和可靠性。在以下情况下测试PowerTap的有效性：i）在跑步机上以不同的踏频（45至120转/分钟）和骑行姿势（站立和坐姿）在不同坡度下进行次最大递增强度（范围为100至420瓦）测试；ii）持续30分钟的连续次最大强度测试；iii）最大强度（8秒冲刺）测试；以及iiii）实际道路骑行测试。通过重复十次次最大递增和连续测试来评估可靠性。结果表明，与科学的SRM模型相比，PowerTap在100至450瓦的次最大强度下具有良好的有效性（平均PO差异为-1.2 +/- 1.3%），但在冲刺运动中的最大PO有效性较低，其有效性似乎取决于传动比。PowerTap在次最大强度下的可靠性与科学的SRM模型相似（PowerTap和SRM的变异系数分别为0.9至2.9%和0.7至2.1%）。PowerTap必须被视为在次最大实际道路骑行和次最大实验室测试中进行PO测量的合适设备。
