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Validity and reliability of the Wattbike cycle ergometer
J Hopker1, S Myers, S A Jobson
1Centre for Sports Studies, University of Kent, Chatham, United Kingdom. j.g.hopker@kent.ac.uk
International Journal of Sports Medicine
|July 29, 2010
Summary
The Wattbike cycle ergometer shows acceptable accuracy compared to the SRM Powermeter, but reliability may vary at lower power outputs, especially in untrained individuals. Coaches should exercise caution with Wattbike test-retest data at low power settings.
Area of Science:
- Sports Science
- Biomechanics
- Exercise Physiology
Background:
- Accurate power measurement is crucial for cycling performance analysis and training.
- The Wattbike and SRM Powermeter are widely used cycle ergometers, but their comparative validity and reliability require thorough investigation.
Purpose of the Study:
- To evaluate the validity and reliability of the Wattbike cycle ergometer against the SRM Powermeter.
- To assess performance across different cadences and power outputs using a dynamic calibration rig (CALRIG) and human participants.
Main Methods:
- Utilized a dynamic calibration rig (CALRIG) to test power outputs from 50-1250 W at 70 and 90 rev/min.
- Conducted repeated trials (3) with trained and untrained participants at work rates ranging from 50-300 W.
- Collected validity and reliability data for both Wattbike and SRM Powermeter.
Main Results:
- Significant differences in power output were observed between SRM and Wattbike on the CALRIG at both cadences (P<0.05).
- Steady-state trials revealed significant differences in recorded power outputs between SRM and Wattbike in both populations (P<0.05).
- Wattbike reliability (CV) was 6.7% in untrained and 2.6% in trained populations, compared to 2.2% and 1.1% for SRM, respectively.
Conclusions:
- The Wattbike demonstrates acceptable accuracy when compared to the SRM Powermeter.
- While generally accurate, the Wattbike's reliability may necessitate caution for coaches and cyclists when interpreting test-retest data at lower power outputs, particularly in untrained individuals.
