Although a self-report questionnaire has already been developed to evaluate maximal oxygen uptake (Vo_2max) indirectly, it is still unclear whether it can accurately predict Vo_2max, especially in middle-aged and older adults. The purpose of this study was to compare differences between directly measured Vo_2max using a cycle ergometer protocol and Vo_2max predicted by a self-report questionnaire. One hundred forty subjects (aged 61.3±8.2) were divided into four groups: control group (group C, n=33), walking group (group W, n=37), trekking group (group T, n=44) and jogging group (group J, n=26). Vo_2max was measured following an incremental protocol using a Monark cycle ergometer (measured Vo_2max) and by a self-report questionnaire (predicted Vo_2max). Pearson correlation coefficients between measured Vo_2max and predicted Vo_2max were significant in all groups. However, standard errors of estimation (SEE) of group J were higher than those reported in previous studies. The difference in measured Vo_2max and predicted Vo_2max correlated significantly with the mean between the measured and predicted Vo_2max in group J. There were significant differences between the measured Vo_2max and the predicted Vo_2max in groups T and J. These results suggest that when the exercise intensity is high, such as in jogging, and consequently when Vo_2max is high, the self-report questionnaire method might underestimate Vo_2max.
