Prediction of maximum oxygen uptake through incremental exercise testing using ventilometry: a cross-sectional study.

BACKGROUND

Cardiopulmonary exercise testing is the main tool assessing cardiorespiratory fitness. However, cardiopulmonary exercise testing devices are expensive and often cannot be used.

OBJECTIVE

The present study sought to develop cardiopulmonary exercise testing equations for estimating maximum oxygen uptake from ergometric testing combined with ventilometry.

METHODS

181 volunteers of both sexes were submitted to cardiopulmonary exercise testing on treadmill using an incremental protocol. Volunteers were randomized into two groups: regression group: composed of 68 women with age 24.7±6.0 years and 54 men aged 21.5±3.9 years; and a cross-validation group composed of 29 women with mean age of 23.8±4.7 years and 30 men with a mean age of 23.1±4.4 years. The estimating equations were developed using multiple stepwise linear regressions; comparison of means was done using a t test and reliability assessed by Cronbach's alpha.

RESULTS

8 independent variables exhibited a significant result for estimating VO: minute ventilation (E) at second ventilatory threshold (VT-II): (E _VT-II); heart rate at VT-II (HR_VT-II); body mass (BM); body mass index (BMI); fat percentage (F%); age; sex; velocity at VT-II (Vel_VT-II); test time of VT-II (T_VT-II) and final test velocity (Vel). Two equations presented more accurate results; for active subjects: Equation = 33.08 + 2.41*(Vel) - 0.32*(F%) + 0.40*(VE_VT-II) - 0.26*(BM) - 0.09*(HR_VT-II); for sedentary subjects: Equation for = 54.65 + 1.37*(T_VT-II) + 8.24*(sex) - 1.26*(BMI) + 0.37*(VE_VT-II) - 0.12*(HR_VT-II).

CONCLUSION

The present study demonstrated that the use of parameters collected during maximal ergometric test combined with ventilometry, improved the accuracy of equations for estimating maximum oxygen uptake.