title: Validity and reliability of the Axiom PowerTrain cycle ergometer when compared with an SRM powermeter.
abstract: The purpose of this study was to determine the validity and the reliability of a stationary electromagnetically-braked cycle ergometer (Axiom PowerTrain) against the SRM power measuring crankset. Nineteen male competitive cyclists completed four tests on their bicycle equipped with a 20-strain gauges SRM crankset: a maximal aerobic power (MAP) test and three 10-min time trials (TTs) with three different simulated slopes (0, 3, and 6 %). The Axiom ergometer overestimated (p <0.05) the SRM power output during the last stage of the MAP test and during TTs, by 5 % and 12 %, respectively. Power output (PO) of the Axiom ergometer drifted significantly (p <0.05) with the time during TT. These findings indicate that the Axiom ergometer does not provide a valid measure of PO compared with SRM. However, the small coefficient of variation (2.2 %) during the MAP test indicates that the Axiom provides a reliable PO and that it can be used e.g. for relative PO comparisons with competitive cyclists during a race season.
authors.affiliation: Laboratoire de Mécanique Appliquée (U.M.R. C.N.R.S. 6604), Université de Franche Comté, Besançon, France. wil.ber@oreka.com
authors.forename: W
authors.initials: W
authors.lastname: Bertucci
authors.forename: S
authors.initials: S
authors.lastname: Duc
authors.forename: V
authors.initials: V
authors.lastname: Villerius
authors.forename: F
authors.initials: F
authors.lastname: Grappe
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology*; D015444:Exercise / Q000502:physiology; D005080:Exercise Test; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D018482:Muscle, Skeletal / Q000502:physiology; D015203:Reproducibility of Results; D013178:Sports Medicine / Q000295:instrumentation* / Q000379:methods; D013647:Task Performance and Analysis