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Int J Sports Med 2010; 31(10): 731-736
DOI: 10.1055/s-0030-1261968
Training & Testing

© Georg Thieme Verlag KG Stuttgart · New York

Validity and Reliability of the Wattbike Cycle Ergometer

J. Hopker1 , S. Myers2 , S. A. Jobson1 , W. Bruce1 , L. Passfield1
  • 1Centre for Sports Studies, University of Kent, Chatham, United Kingdom
  • 2University of Chichester, Faculty of Sport Education and Social Sciences, Chichester, United Kingdom
Further Information

Publication History

accepted after revision June 20, 2010

Publication Date:
27 July 2010 (online)

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Abstract

The purpose of this study was to assess the validity and reliability of the Wattbike cycle ergometer against the SRM Powermeter using a dynamic calibration rig (CALRIG) and trained and untrained human participants. Using the CALRIG power outputs of 50–1 250 W were assessed at cadences of 70 and 90 rev.min−1. Validity and reliability data were also obtained from 3 repeated trials in both trained and untrained populations. 4 work rates were used during each trial ranging from 50–300 W. CALRIG data demonstrated significant differences (P<0.05) between SRM and Wattbike across the work rates at both cadences. Significant differences existed in recorded power outputs from the SRM and Wattbike during steady state trials (power outputs 50–300 W) in both human populations (156±72 W vs. 153±64 W for SRM and Wattbike respectively; P<0.05). The reliability (CV) of the Wattbike in the untrained population was 6.7% (95%CI 4.8–13.2%) compared to 2.2% with the SRM (95%CI 1.5–4.1%). In the trained population the Wattbike CV was 2.6% (95%CI 1.8–5.1%) compared to 1.1% with the SRM (95%CI 0.7–2.0%). These results suggest that when compared to the SRM, the Wattbike has acceptable accuracy. Reliability data suggest coaches and cyclists may need to use some caution when using the Wattbike at low power outputs in a test-retest setting.

Key words

cycling - ergometry - calibration - power output - testing - talent identification

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Correspondence

James Hopker

University of Kent

Centre for Sport Studies

Chatham Maritime

ME4 4AG Medway

United Kingdom

Phone: +44/1634/888814

Fax: +44/1634/888809

Email: j.g.hopker@kent.ac.uk