Int J Sports Med 2009; 30(2): 107-112
DOI: 10.1055/s-0028-1103285
Training & Testing

© Georg Thieme Verlag KG Stuttgart · New York

Accuracy of the Velotron Ergometer and SRM Power Meter

C. R. Abbiss 1 , M. J. Quod 2 , G. Levin 1 , D. T. Martin 2 , P. B. Laursen 1
  • 1School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Perth, Australia
  • 2Department of Physiology, Australian Institute of Sport, Canberra, Australia
Further Information

Publication History

accepted after revision July 15, 2008

Publication Date:
28 January 2009 (online)


The purpose of this study was to determine the accuracy of the Velotron cycle ergometer and the SRM power meter using a dynamic calibration rig over a range of exercise protocols commonly applied in laboratory settings. These trials included two sustained constant power trials (250 W and 414 W), two incremental power trials and three high-intensity interval power trials. To further compare the two systems, 15 subjects performed three dynamic 30 km performance time trials. The Velotron and SRM displayed accurate measurements of power during both constant power trials (<1% error). However, during high-intensity interval trials the Velotron and SRM were found to be less accurate (3.0%, CI=1.6–4.5% and −2.6%, CI=−3.2–−2.0% error, respectively). During the dynamic 30 km time trials, power measured by the Velotron was 3.7±1.9% (CI=2.9–4.8%) greater than that measured by the SRM. In conclusion, the accuracy of the Velotron cycle ergometer and the SRM power meter appears to be dependent on the type of test being performed. Furthermore, as each power monitoring system measures power at various positions (i.e. bottom bracket vs. rear wheel), caution should be taken when comparing power across the two systems, particularly when power is variable.



C. R. Abbiss, BSc. Sports Science 

School of Exercise

Biomedical and Health Sciences

Edith Cowan University

100 Joondalup drive

6168 Perth


Phone: +61/8/6304 51 56

Fax: +61/8/6304 50 36

Email: [email protected]