The Prediction of ‘Maximal’ Oxygen Consumption Using a New Progressive Step Test

Abstract

A description is given of a ‘ progressive ’ step test where the speed of ascent of two 9 in. steps is progressively increased. The validity of this test is established in terms of (1) the rate of approach to a steady-state, (2) a comparison of measured variables in the ‘ steady-state ’ and ‘ progressive ’ tests, and (3) a comparison of data for ‘ maximal ’ oxygen intake with predictions from the ‘ progressive ’ and ‘ steady-state ’ step tests. The 9 in. step is subjectively more comfortable than an 18 in. step teat. The efficiency of working is independent of step height over the range 9-18 in., but varies with the speed of stepping. Variations in efficiency are no greater than for the bicycle ergometer at comparable rates of working. Methods of predicting ‘ maximal ’ oxygen uptake are critically reviewed. The pulse rates during performance of the 9 in. progressive step test agree quite well with Åstrand's findings at comparable levels of oxygen consumption. When the test is performed in the laboratory, the coefficient of correlation between observed and predicted ‘ maximal ’ oxygen uptake, using the Åstrand nomogram, is 0·872, with an 8 per cent underestimate of the ‘ maximal ’ value. The corresponding coefficient for a modified extrapolation according to Maritz et al. (1961) is 0·858, with 5-6 per cent underestimate of the ‘ maximal ’ value, while for the respiratory quotient prediction of Issekutz et al. (1962) the coefficient is 0·921, with no systematic underestimation of the ‘ maximal ’ value. Good predictions of ‘ maximal ’ oxygen intake can be obtained by each of these simple procedures. More elaborate combinations of test variables are required primarily to explore those aspects of ‘ fitness ’ and ‘ training ’ which are related to aerobic work capacity.