Abstract

An equation was developed to estimate maximal oxygen uptake (VO2max) based on a single submaximal stage of a treadmill walking test. Subjects (67 males, 72 females) aged 20-59 yr completed 4-min sstages at 0.5, and 10 grades walking at a constant speed (2.0-4.5 mph) and then performed a VO2max test. Heart rate and respiratory gas exchange variables were measured during the test. Multiple regression analysis (N = 117) to estimate VO2max from the 4-min stage at 5 grade yielded the following model (R*R = 0.86: SEE = 4.85 ml/kg/min): VO2max = 15.1 + 21.8*SPEED (mph) - 0.327*HEART RATE (bpm) - 0.263*SPEED*AGE (yr) + + 0.00504*HEART RATE*AGE + 5.98*GENDER (0 = Female: 1 = Male). The constant and all coefficients were highly significant. To assess the accuracy of the model in a cross-validation group (N = 22), an estimated VO2max value was obtained using the above model. Estimated VO2max then was regressed on observed VO2max xyielding the following equation (R*R = 0.92): ESTIMATED VO2max = 0.15 + 1.03*OBSERVED VO2max. The intercept and lsope of this equation were not significantly different from 0 and 1, respectively. For 90.9 of the subjects in the cross-validation group, residual scores were within the range of +/- 5 ml/kg/min. In conclusion, this submaximal walking test based on a single stage of a treadmill protocol provides a valid and time-efficient method for estimating VO2max. Verf.-Referat