title: [Reliability of Selected Parameters of Cycling Ergospirometry from the PowerCube-Ergo Respiratory Gas Analyser].
abstract: This study aimed to investigate the reliability of 1) the key parameters of cycling ergospirometry (maximum power output [Pmax] and oxygen uptake [V̇O2peak], ventilatory thresholds 1 [VT 1] and 2 [VT 2], and cycling efficiency [CE] and gross efficiency [GE]), 2) the commonly used parameters to quantify exhaustion (maximum heart rate [HFmax], respiratory quotient [RQmax], blood lactate concentration [BLAmax], and ratings of perceived exhaustion [RPEmax]), and 3) the kinetics of exercise induced gas exchange measurements (oxygen uptake [V̇O2], carbon dioxide output [V̇CO2], and minute ventilation [V̇E]) using the PowerCube-Ergo metabolic system in consideration of international statistical recommendations. 12 women and 12 men (28 ± 4 years; 23.2 ± 2.4 kg/m(2)) performed two cycling tests (20 watt/min) separated by one week. The reliability was calculated based on differences in means (t test and effect sizes), retest correlation (intraclass correlation coefficient [ICC]), and within-subject variation (standard error of measurement [SEM]). Of the key parameters of cycling ergospirometry, an excellent reliability (ICC ≥ 0.969; p = 0.000) and high accuracy (%SEM ≤ 4.6) were found for Pmax, V̇O2peak, and VT 1. Of the most commonly used parameters to quantify exhaustion, an excellent reliability (ICC = 0.922; p = 0.000) and high accuracy (%SEM = 1.0) existed only for HFmax. The gas exchange measurements (V̇O2, V̇CO2 und V̇E) of the PowerCube-Ergo were all excellently reliable (ICC ≥ 0,991; p = 0.000) and the accuracy of V̇O2 (SEM = 0.10 l/min) and V̇E (SEM = 3.13 l/min) fulfilled the quality guidance of exercise physiology laboratories. For future studies and practical purposes, the results are vital for the decision as to whether a difference between two tests represents a true intervention effect or just a measurement error and for the estimation of required sample sizes.
authors.affiliation: Arbeitsbereich Bewegungs- und Trainingswissenschaft, Bergische Universität Wuppertal, Deutschland.
authors.forename: M W
authors.initials: MW
authors.lastname: Hoppe
authors.affiliation: Arbeitsbereich Integrative und Experimentelle Trainingswissenschaft, Julius-Maximilians-Universität Würzburg, Deutschland.
authors.forename: B
authors.initials: B
authors.lastname: Sperlich
authors.affiliation: Arbeitsbereich Bewegungs- und Trainingswissenschaft, Bergische Universität Wuppertal, Deutschland.
authors.forename: C
authors.initials: C
authors.lastname: Baumgart
authors.affiliation: Arbeitsbereich Bewegungs- und Trainingswissenschaft, Bergische Universität Wuppertal, Deutschland.
authors.forename: M
authors.initials: M
authors.lastname: Janssen
authors.affiliation: Arbeitsbereich Bewegungs- und Trainingswissenschaft, Bergische Universität Wuppertal, Deutschland.
authors.forename: J
authors.initials: J
authors.lastname: Freiwald
mesh_terms: D000328:Adult; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005080:Exercise Test / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013147:Spirometry / Q000295:instrumentation*