Maier Thomas, Schmid Lucas, Müller Beat, Steiner Thomas, Wehrlin Jon Peter
Section for Elite Sport, Swiss Federal Institute of Sport, Magglingen, Switzerland.
Int J Sports Med. 2017 Jun;38(6):456-461. doi: 10.1055/s-0043-102945. Epub 2017 May 8.
The aim of this study was to compare the accuracy among a high number of current mobile cycling power meters used by elite and recreational cyclists against a first principle-based mathematical model of treadmill cycling. 54 power meters from 9 manufacturers used by 32 cyclists were calibrated. While the cyclist coasted downhill on a motorised treadmill, a back-pulling system was adjusted to counter the downhill force. The system was then loaded 3 times with 4 different masses while the cyclist pedalled to keep his position. The mean deviation (trueness) to the model and coefficient of variation (precision) were analysed. The mean deviations of the power meters were -0.9±3.2% (mean±SD) with 6 power meters deviating by more than±5%. The coefficients of variation of the power meters were 1.2±0.9% (mean±SD), with Stages varying more than SRM (p<0.001) and PowerTap (p<0.001). In conclusion, current power meters used by elite and recreational cyclists vary considerably in their trueness; precision is generally high but differs between manufacturers. Calibrating and adjusting the trueness of every power meter against a first principle-based reference is advised for accurate measurements.
本研究的目的是将大量目前精英和业余自行车手使用的移动自行车功率计的准确性与基于第一原理的跑步机骑行数学模型进行比较。对32名自行车手使用的来自9个制造商的54个功率计进行了校准。当自行车手在电动跑步机上向下滑行时，调整一个后拉系统以抵消下坡力。然后，在自行车手踩踏板以保持其位置的同时，用4种不同质量的物体对系统加载3次。分析了功率计相对于模型的平均偏差（准确性）和变异系数（精密度）。功率计的平均偏差为-0.9±3.2%（平均值±标准差），6个功率计的偏差超过±5%。功率计的变异系数为1.2±0.9%（平均值±标准差），Stages的变异程度大于SRM（p<0.001）和PowerTap（p<0.001）。总之，精英和业余自行车手目前使用的功率计在准确性方面差异很大；精密度一般较高，但不同制造商之间存在差异。建议针对基于第一原理的参考对每个功率计的准确性进行校准和调整，以进行准确测量。
