Criterion validity of the Ekblom-Bak and the Åstrand submaximal test in an elderly population

Abstract

Purpose: The aim of this study was to validate the submaximal Ekblom-Bak test (EB-test) and the Åstrand test (Å-test) for an elderly population.

Methods: Participants (n = 104), aged 65-75 years, completed a submaximal aerobic test on a cycle ergometer followed by an individually adjusted indirect calorimetry VO₂max test on a treadmill. The HR from the submaximal test was used to estimate VO₂max using both the EB-test and Å-test equations.

Results: The correlation between measured and estimated VO₂max using the EB method and Å method in women was r = 0.64 and r = 0.58, respectively and in men r = 0.44 and r = 0.44, respectively. In women, the mean difference between estimated and measured VO₂max was - 0.02 L min^-1 (95% CI - 0.08 to 0.04) for the EB method and - 0.12 L min^-1 (95% CI - 0.22 to - 0.02) for the Å method. Corresponding values for men were 0.05 L min^-1 (95% CI - 0.04 to 0.14) and - 0.28 L min^-1 (95% CI - 0.42 to - 0.14), respectively. However, the EB method was found to overestimate VO₂max in men with low fitness and the Å method was found to underestimate VO₂max in both women and men. For women, the coefficient of variance was 11.1%, when using the EB method and 19.8% when using the Å method. Corresponding values for men were 11.6% and 18.9%, respectively.

Conclusion: The submaximal EB-test is valid for estimating VO₂max in elderly women, but not in all elderly men. The Å-test is not valid for estimating VO₂max in the elderly.

Keywords: Cardiorespiratory fitness; Elderly; Oxygen uptake; Public health; Submaximal test; Validity.