Quantification and Verification of Cardiorespiratory Fitness in Adults with Prehypertension

Low cardiorespiratory fitness is associated with increased risk of hypertension and atherosclerosis in adults with prehypertension. The purpose of this study was to quantify cardiorespiratory fitness and to examine the utility of supramaximal constant-load verification testing for validating maximal oxygen uptake (VO_2max) attainment in adults with prehypertension.

Eleven adults (four women) with prehypertension (22.5 ± 2.9 y; body mass index (BMI): 24.6 ± 3.2 kg·m²) underwent an incremental exercise test followed 15 min later by a verification test at 105% of maximal work rate on a cycle ergometer.

There was no statistical difference in VO₂ between the incremental (2.23 ± 0.54 L·min^-1) and verification tests (2.28 ± 0.54 L·min^-1; p = 0.180). Only three out of eleven participants had a higher VO₂ during the verification when compared with the incremental test. If the verification test had not been conducted, one participant would have been incorrectly classified as having low cardiorespiratory fitness based on incremental test results alone.

Verification testing validates the attainment of VO_2max and can potentially reduce the over-diagnosis of functional impairment (i.e., deconditioning) in adults with prehypertension.