A Modified Submaximal Cycle Ergometer Test Designed to Predict Treadmill VO_2max

Abstract

This study sought to develop a modified submaximal cycle ergometer test designed to predict maximal oxygen consumption (VO_2max) obtained on a treadmill. Volunteers (N = 156; women = 80, men = 76) with ages from 18 to 39 years old successfully performed a submaximal cycle protocol on a stationary cycle ergometer and a maximal graded exercise test (GXT) on a treadmill. Open circuit calorimetry was used during the GXT to measure VO_2max. Multiple linear regression resulted in the following prediction equation: VO_2max = 85.447 + 9.104 χSex (0 = women; 1 = men) - 0.2676 χAge (year) - 0.4150 χBody Mass (kg) + 0.1317 χPower Output (W) - 0.1615 χHeart Rate (bpm), which had acceptable validity (r = .88, standard error of estimate [SEE] = 3.12 ml· kg^-1 · min^-1). Selected participants (n = 34) performed the submaximal cycle ergometer test twice (within a 5-day period), yielding a test-retest intraclass reliability coefficient of r = .95 for VO_2max estimations across days. The reliability of VO_2max estimates for women (r = .93) was greater than that for men (r = .74). Cross-validation results were also acceptable using predicted residual sum of squares (PRESS; r^PRESS = .87, SEE^PRESS = 3.24 ml · kg^-1 min^-1), which suggests that the new equation should yield acceptable accuracy when it is applied to a similar, but independent sample of adults. In summary, the modified cycle ergometer test developed in this study yields relatively accurate estimates of treadmill VO_2max in young adults, requires only a moderate level of exertion, and appears to be a convenient and time-efficient means of estimating cardiorespiratory fitness.