Accuracy Of Predicting Vo2max By The Extrapolation Method

Abstract

PURPOSE The purpose of this study was to test parameters that may affect the accuracy of predicting Vo2max by the extrapolation method. METHODS A total of 60 Low Risk (ACSM GETP 6th Ed.) males and females (27.4 ± 6.9 years, Height = 170.6 ± 10.6 cm, Weight = 68.7 ± 12.5 kg, Body Fat = 15.6 ± 5.3%, BMI = 23.4 ± 2.6 kg/m2) completed 2 maximal and 1 submaximal treadmill tests, each having a 4 minute warmup stage and 2 minute stages that increased in workload by approximately 1.5 METs. Oxygen consumption was measured during each test (ParvoMedics TrueMax) and Vo2max was determined using standard criteria from the 2 max tests. Predicted Vo2max was determined by extrapolation method using linear regression of heart rate (Quinton Q 4500) and Vo2. The relationship of predicted Vo2max to measured Vo2max was determined by Pearson's Correlation. RESULTS Mean Vo2max was 2.919 ± 0.82 L/min, with the most accurate prediction of Vo2max occurring when measured Vo2 for each stage was used instead of Vo2 predicted from ACSM metabolic equations (Mean Vo2max = 2.831 ± 0.855 L/min, R = 0.915, SEE = 0.347 and 3.449 ± 0.854* L/min, R = 0.855, SEE = 0.43, respectively, *P ≤ .001). Prediction accuracy also improved as heart rates used in the prediction model approached 85% of age-predicted maximum (2.817 ± 0.851 L/min, R = 0.917, SEE = 0.33). CONCLUSIONS The results of this study demonstrate that Vo2max prediction accuracy by the extrapolation method is improved when the prediction model includes known Vo2 instead of Vo2 estimated from ACSM equations and by using heart rates that are closer to 85% age-predicted heart rate maximum.