Validity and feasibility of four standardized aerobic fitness tests in patients with depression: A cross-sectional study.

The objective of this study was to examine the validity and feasibility of four standardized aerobic fitness tests to either measure V˙ Opeak or to estimate V˙ Omax (e V˙ Omax) in patients with major depression disorder (MDD). To this end, all subjects (n = 43) performed one maximal cardiopulmonary exercise test with gas exchange measurement (CPET) on a bicycle ergometer. Additionally, three submaximal tests (Åstrand-Rhyming bicycle ergometer test [ART], Physical work capacity test [PWC], and 6-min walk test [6MWT]) were performed within two weeks in counterbalanced order.