Efficacy of estimating VO2max with the Heart Rate Ratio Method in middle-aged and older adults.

Abstract

Investigate difference, agreement, and bias between maximal oxygen consumption (VO2max) measured by indirect calorimetry and the Heart Rate Ratio Method (HRRM) for estimating VO2max using measured and age-predicted maximum heart rate (HRmax) in a sample of middle-aged and older adults. Eleven men and nine women (age: 61.8 ± 8.5years, VO2max: 36.6 ± 9.5mL/kg/min, N = 20) had their VO2max measured via a maximal graded exercise test and confirmed using a verification bout on a treadmill ergometer. Participants' VO2max was estimated via the HRRM using measured and age-predicted HRmax. Difference, agreement, and bias between methods were assessed using a one-way repeated measures Analysis of Variance (ANOVA), Lin's concordance correlation coefficient, and Bland-Altman plots, respectively. There were no statistical differences between methods of assessing VO2max, F(1.13, 21.47) = 0.583, p = 0.473, generalized eta-squared = 0.012. The standard error of the estimate (SEE) for the HRRM using measured or predicted HRmax was 5.2% and 5.6% of the mean VO2max, respectively. Both HRRM predictions had poor agreement with VO2max (rc ≤ 0.40). There was a systematic bias to underestimate as VO2max increased for HRRM using measured HRmax, F(1, 18) = 17.40, p < 0.001, and when using an age-predicted HRmax, F(1, 18) = 13.39, p = 0.002. Both versions of the HRRM have poor agreement, relatively large SEEs, and a bias to misrepresent VO2max. When possible, VO2max should be measured via a maximal graded exercise test with indirect calorimetry for middle-aged and older adults.