Prediction of the maximum oxygen consumption (VO_2max) for young Saudi females using exercise parameters

Maximum oxygen consumption (VO_2max), an essential indicator of integrated function of the cardiovascular, respiratory, and muscular systems, is an excellent predictor of all-cause morbidity and mortality. Direct measurement is a sophisticated procedure which for some individuals is difficult to perform. The use of international formulae leads to overestimation or underestimation of values. Therefore, the present study aimed to generate a best-fit VO2max prediction formula for young Saudi females.

One hundred and two randomly selected young healthy Saudi females (19-25 years) with normal body mass index (18.5-24.99 kg m^-2) and sedentary lifestyle underwent maximum cardiopulmonary exercise testing on cycle ergometer when using breath-by-breath analyzing system. Hemodynamic and ventilatory parameters were assessed before and during the maximum exercise. Significantly correlated exercise and nonexercise parameters enterd in multiple linear regression analysis to find the best-fit model, and used to generate a VO_2max prediction formula.

The mean measured VO_2max was 1449.1 ± 233.92 ml min^-1. The VO_2max prediction formula was 1304.193 ± 17.902 × body weight + 43.857 × time until exhaustion - 6.83 × maximum heart rate. The mean calculated VO_2max was 1449.14 ± 143.97 ml min^-1. No statistically significant difference was observed between the measured and calculated VO_2max. The Bland-Altman test for the limit of agreement was performed and showed good agreement between the two values with a minute proportional bias. The standard error of the estimate was 156.34, which is approximately 10.6% of the mean measured VO_2max. Reliability analysis yielded a Cronbach's alpha of 0.709.

This study presents a reliable and valid VO_2max prediction formula for young Saudi females. This nationally generated formula is far more representative of the VO_2max value than international formulae. We recommend the implementation of this formula and an investigation of its validity in other Saudi population groups.