RESUMO
PURPOSE: This study aimed to cross-validate a recently proposed equation for the prediction of maximal oxygen uptake (VËO2max) in cycling exercise by using the average power output normalized by the body mass from a 5-minute time trial (RPO5-min) as the independent variable. Further, the study aimed to update the predictive equation using Bayesian informative prior distributions and meta-analysis. METHODS: On different days, 49 male cyclists performed an incremental graded exercise test until exhaustion and a 5-minute time trial on a stationary cycle ergometer. We compared the actual VËO2max with the predicted value obtained from the RPO5-min, using a modified Bayesian Bland-Altman agreement analysis. In addition, this study updated the data on the linear regression between VËO2max and RPO5-min, by incorporating information from a previous study as a Bayesian informative prior distribution or via meta-analysis. RESULTS: On average, the predicted VËO2max using RPO5-min underestimated the actual VËO2max by -6.6 mL·kg-1·min-1 (95% credible interval, -8.6 to -4.7 mL·kg-1·min-1). The lower and upper 95% limits of agreement were -17.2 (-22.7 to -12.3) and 3.8 (-1.0 to 9.5) mL·kg-1·min-1, respectively. When the current study's data were analyzed using the previously published data as a Bayesian informative prior distribution, the accuracy of predicting sample means was found to be better when compared with the data combined via meta-analyses. CONCLUSIONS: The proposed equation presented systematic bias in our sample, in which the prediction underestimated the actual VËO2max. We provide an updated equation using the previous one as the prior distribution, which could be generalized to a greater audience of cyclists.