UBC Theses and Dissertations
Electronic versus mechanical loading in the determination of peak oxygen consumption in bicycle ergometry Clarke, Mark Anthony
The purpose of the study was to determine if differences in the loading (or braking) systems of two different types of stationary bicycle ergometers (Monark and Dynavit models) influenced the performances of subjects in similar submaximal and maximal exercise. A maximal treadmill test, also performed by the subjects, was used as a criterion measure with which the maximal bicycle ergometer test results were compared. The possibility of finding differences in the performances of subjects on the two bicycle ergometers and of similarities between maximal bicycle and treadmill tests would appear to have important implications for laboratory and field testing procedures, as well as for costs of equipment used in physical fitness work and exercise physiology. Thirteen non-trained, college-aged male volunteers, 18 to 26 years, took part in the study. Each subject performed one test on each of three pieces of testing equipment; the Dynavit bicycle, the Monark bicycle, and the treadmill. Each test consisted of a maximal exercise bout of a continuous, incremental nature, during which time the appropriate physiological data was recorded. There was an interval of at least three days between tests, the subjects being assigned treatment orders via a Latin square design. Principal variables examined during maximal exercise were total work time and peak oxygen consumption; at submaximal exercise levels they were oxygen uptake and heart rate. Other variables examined, although not of central importance to the study, were maximal heart rate, maximal oxygen pulse, submaximal oxygen pulse, and subjective response to exercise. A Beckman Metabolic Measurement Cart, interfaced with a Hewlett-Packard Data Acquisition system, recorded the pertinent physiological data, which was then analyzed by the use of one and two-way ANOVA's and Newman-Keuls post hoc tests where appropriate. The results indicated no significant differences in total work time, peak oxygen consumption, maximal heart rate, maximal oxygen pulse, submaximal heart rate, submaximal oxygen uptake, submaximal oxygen pulse, and subjective response to exercise between the two bicycle ergometers. Only the treadmill elicited higher values of peak oxygen consumption than either of the cycle ergometers. This Tack of a significant difference suggests that although there may be structural differences in the loading (or braking) systems of the Dynavit and Monark ergometers, these differences are not reflected by the subjects' physiological responses to comparable levels of exercise intensity. Thus the results indicate that these bicycles could be used interchangeably for such predictive tests of physical work capacity as the Astrand-Ryhming Predicted Oxygen Uptake Test or the Modified Sjostrand PWC Test.
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