A Generalized Equation for Prediction of VO2peak from a Step Test

Abstract

This study aimed to develop an equation to reduce variability of VO₂peak prediction from a step test and compare VO₂peak prediction from the new equation to the Queen's College Step Test (QCST). The development group (n=86; 21.7±2 years) was utilized to develop the SDState step test equation to predict relative VO₂peak. The cross-validation group (n=99; 21.6±2 years) was used to determine the validity of the SDState step test VO₂peak prediction equation. A regression analysis was used to identify the best model to predict VO₂peak. Analysis of variance (ANOVA) was further used to determine differences among predicted and measured VO₂peak values. Forward stepwise multiple regression identified age, sex, abdominal circumference, and active heart rate at the 3-min mark of the step test to be significant predictors of VO₂peak (mL·kg^-1·min^-1). No differences among measured VO₂peak (47.3±7.1 mL·kg^-1·min^-1) and predicted VO₂peak (QCST, 46.9±9.3 mL·kg^-1·min^-1; SDState 48.3±5.7 mL·kg^-1·min^-1) were found. Pearson correlations, ICC, SEE, TEE, Bland-Altman plots, and Mountain plots indicate the SDState step test equation provides less variation in the prediction of VO₂peak compared to the QCST. The SDState step test equation is effective for predicting VO₂peak from the YMCA step test in young, healthy adults.