ASSESSING VO2MAX IN EPIDEMIOLOGIC STUDIES - MODIFICATION OF THE ASTRAND-RYHMING TEST

Abstract

Direct measurement of maximum O2 uptake (.ovrhdot.VO2 max) is the standard index of cardiorespiratory fitness but is practical only in a laboratory setting. Current cycle ergometer tests to estimate .ovrhdot.VO2 max are difficult for inactive adults because most of these tests are lengthy and require a high initial exercise rate. An existing test, the Astrand-Ryhming test, was modified to avoid these problems. .ovrhdot.VO2 max was measured directly and estimated by means of the present protocol in a test group of 50 men and women, 10 for each decade between 20 and 70 yr, to develop multiple regression equations to correct for variations due to age. Equations for each sex were computed with directly measured .ovrhdot.VO2 max as the dependent variable and with the estimated .ovrhdot.VO2 max and age as independent variables. The validity of these equations was tested by deriving data from an additional 63 subjects (validity group). No significant differences were found between the directly measured .ovrhdot.VO2 max and the .ovrhdot.VO2 max estimated by the present protocol and equations. For each group, the mean difference between the 2 values was < 120 ml .cntdot. min-1. Correlations between the measured and estimated .ovrhdot.VO2 max ranged from 0.92-0.93 for the age groups. This modification of the Astrand-Ryhming protocol accurately estimates .ovrhdot.VO2 max and is safe and suitable for assessing cardiovascular fitness in epidemiologic studies of people between the ages of 20-70 yr.