Comparison of Cardiovascular Responses Between Upright and Recumbent Cycle Ergometers in Healthy Young Volunteers Performing Low-Intensity Exercise: Assessment of Reliability of the Oxygen Uptake Calculated by Using the ACSM Metabolic Equation

Abstract

Saitoh M, Matsunaga A, Kamiya K, Ogura MN, Sakamoto J, Yonezawa R, Kasahara Y, Watanabe H, Masuda T. Comparison of cardiovascular responses between upright and recumbent cycle ergometers in healthy young volunteers performing low-intensity exercise: assessment of reliability of the oxygen uptake calculated by using the ACSM metabolic equation. Objectives To clarify (1) differences in cardiovascular response during low-intensity exercise in the upright versus the recumbent position, and (2) whether the oxygen uptake (V̇ o 2) calculated by the American College of Sports Medicine (ACSM) metabolic equation reflects the actual V̇ o 2 at low-intensity testing. Design Repeated-measures comparison study. Setting University research laboratory. Participants Thirty-one healthy, young volunteers (age, 23±2y). Interventions Not applicable Main outcome measures Blood pressure, rate pressure product (RPP), V̇ o 2, oxygen pulse, carbon dioxide output (V̇ co 2), and ventilatory equivalent (V̇ e) were measured during graded exercise testing using upright and recumbent cycle ergometers. The estimated V̇ o 2 was calculated by using the ACSM metabolic equation. Results Systolic blood pressure, RPP, V̇ o 2, oxygen pulse, V̇ co 2, and V̇ e at 15 or 30W were significantly higher in the recumbent position than in the upright one ( P<.05), however, no significant differences were observed at 50 and 70W. The estimated V̇ o 2 during exercise was significantly higher than the actual one, at every level of intensity, from 15 to 70W ( P<.05). Conclusions Cardiovascular responses should be carefully monitored even during low-intensity exercise using a recumbent cycle ergometer. The V̇ o 2 estimated using the ACSM metabolic equation did not reflect the actual V̇ o 2 during low-intensity exercise at 70W or less.