Cardiovascular responses during upright and semi-recumbent cycle ergometry testing

Abstract

To compare cardiovascular (CV) responses during cycle ergometry testing, 20 unmedicated mild hypertensive subjects (10 male, 10 female; mean age = 47.9 yr) underwent exercise testing on an upright (UP) cycle and a semi-recumbent (SR) cycle. Tests were administered in counterbalanced order on two separate days. Heart rate (HR), blood pressure (BP), ventilation (VE), and rate pressure product (RPP) were recorded at absolute workloads (1.0 and 1.5 l.min-1) as well as at relative workloads (50, 75, and 90% of VO2 peak). In addition, the CV variables were measured at rest and peak exercise for each position. At absolute submaximal levels, women had higher HR, VE, and RPP values in both positions, reflecting responses at a greater percentage of their maximum exercise capacity. At relative workloads, HRs were significantly lower at rest and at 75 and 90% VO2 peak in the SR position. Men had greater systolic blood pressure (SBP) and RPP in both positions, and RPP was significantly lower at rest and at 75 and 90% VO2 peak in the SR position. Women displayed lower VE at all relative workloads. At peak exercise, subjects achieved significantly higher peak heart rates on the upright cycle (UP = 163 bpm, SR = 157 bpm). The UP cycle was associated with higher levels of peak VO2. The ability to achieve a higher HR and greater VO2 at peak exercise suggests that the UP cycle ergometer may be a preferable mode to the SR ergometer for evaluating maximal exercise performance among patients with mild hypertension.