Comparison Between Direct and Indirect Methods for the Determination of the Maximal Oxygen Uptake in Female Runners

Mailing address: Fabiana Andrade Machado Departamento de Educação Física Universidade Estadual de Maringá Avenida Colombo, 5.790 – Bloco M06 – sala 06 – 87020-900 Maringá, PR E-mails: [email protected], [email protected] ABSTRACT The aim of this study was to compare the values of O2max directly determined by an ergospirometry system, with values indirectly predicted by the ErgoPC system during maximal exercise test underwent by female runners. Twenty trained female runners participated in the study (42.7 ± 6.4 years-old, height 1.64 ± 0.04m, body mass 58.3 ± 5.8kg, body mass index (BMI) 21.7 ± 1.9kg/m2 and body fat percentage 22.3 ± 3.5. The subjects were evaluated for body composition and underwent a progressive exercise test on treadmill (Inbrasport, Porto Alegre, RS, Brazil) to measure the aerobic fitness ( O2max). The initial speed was 7km/h with increments of 1km/h every three minutes and constant inclination of 1% was kept throughout the test. The participants were encouraged to remain in the test as long as possible until voluntary exhaustion. The gas analyzer VO2000 Inbrasport Spirometer, Porto Alegre, Brazil was used for the direct measurement of O2max, while for the indirect measurement of O2max the ErgoPC program with the prediction formula from Foster (1996) was used. Statistical analysis was performed by Student’s t test for the comparison of the values of O2max obtained in the direct and indirect test, and Pearson’s correlation was applied to correlate these two variables. Direct measurement of O2max showed a value of 51.8 ± 6.8ml/kg/min and indirect one of 42.8 ± 3.7ml/kg/min. The comparison between both results was significantly different. The correlation between the values of O2max was r = 0.67. Thus, the results show that the obtained O2max by an indirect way underestimates the value of the direct measurement.