Affiliations: Center of Health Sciences and Sport, Santa Catarina State Universiy, Santa Catarina, Brazil
Correspondence:
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Corresponding author: Vitor P. Costa, Center for Health and Sport Science, Santa Catarina State University, Rua Pascoal Simone, 358, Coqueiros, Florianópolis, Santa Catarina State, Brazil. Tel.: +55 48 9649 1169; E-mail: vitor.costa@udesc.br.
Abstract: BACKGROUND: Stages device is an affordable power meter used by several professional and competitive cyclists. However, few studies have investigated its validity and reliability. OBJECTIVE: The aim of this study was to analyze the validity and the reliability of the Stages mountain biking power meter. METHODS: Twenty-six cyclists (age: 35 ± 7 years, VO2max: 58 ± 7 ml⋅kg-1⋅min-1) completed six testing sessions within a 4-week period. Cyclists performed an incremental exercise test, a 5-min time trial (TT), and a 20-min TT in different days using the Velotron cycle ergometer attached with the power meter. RESULTS: The power output of the Stages was significantly lower during each step of the incremental exercise test (11.8 to 16.4%) and performance testing (∼ 18%) compared with the cycle ergometer. Bland Altman plots presented high bias and limits of agreements when comparing the power output of the Stages and Velotron. In general, high coefficient of variation was found for the power and cadence of the Velotron and Stages, except for the Velotron’s power during the 20-min TT. CONCLUSIONS: The interchangeable use of the power from the Velotron and Stages is not recommended due to the observed high within-subject variation.
Keywords: Cyclists, power output, Stages, mountain biking, time trial
