Treadmill validation of an over-ground walking test to predict peak oxygen consumption

Summary

The purpose of this study was to determine whether a test developed to predict maximal oxygen consumption (VO_2max) during over-ground walking, was similarly valid as a predictor of peak oxygen consumption (VO₂) when administered during a 1-mile (1.61 km) treadmill walk. Treadmill walk time, mean heart rate over the last 2 full min of the walk test, age, and body mass were entered into both generalized (GEN Eq.) and gender-specific (GSP Eq.) prediction equations. Overall results indicated a highly significant linear relationship between observed peakVO₂ and GEN Eq. predicted values (r=0.91), a total error (TE) of 5.26 ml · kg⁻¹ · min⁻¹ and no significant difference between observed and predicted peakVO₂ mean values. The peakVO₂ for women (n = 75) was predicted accurately by GSP Eq. (r = 0.85; TE = 4.5 ml · kg⁻¹ · min⁻¹), but was slightly overpredicted by GEN Eq. (overall mean difference = 1.4 ml · kg⁻¹ · min⁻¹;r=0.86; TE = 4.56 ml · kg⁻¹ · min⁻¹). No significant differences between observed peakVO₂ and either GEN Eq. (r=0.85; TE=4.3 ml · kg⁻¹ · min⁻¹) or GSP Eq. (r=0.85; TE = 4.8 ml · kg⁻¹ · min⁻¹)predicted values were noted for men (n=48) with peakVO₂ values less than or equal to 55 ml · kg⁻¹ · min⁻¹. However, both equations significantly underpredicted peakVO₂ for the remaining high peakVO₂ men (n = 22). In conclusion, the over-ground walking test, when administered on a treadmill, is a valid method of predicting peakVO₂ but underpredicts peakVO₂ of subjects with observed high peakVO₂ values.