A Systematic Review of Cardiorespiratory Fitness Testing in Major Depression

Background Depression is associated with physical inactivity, low cardiorespiratory fitness (CRF), and poor physical health compared with the general population. Various protocols are employed to determine CRF studies of people experiencing depression, but standardized methods are absent from the literature. Thus, the aim of the present review is to systematically examine the protocols reported to determine CRF in patients with major depressive disorder (MDD). Methods Replicating a previously published search strategy, the present review sourced relevant studies from PubMed, PsycInfo, Embase, CINAHL, MEDLINE, Psychology and Behavioural Sciences Collection, and SPORTDiscus from August 2015 to February 2021. Details of CRF testing protocols were extracted into a preprepared form for analysis. Results Twenty-three studies met the inclusion criteria, including those from a previous review of CRF in people with MDD. Twelve included studies employed maximal testing protocols, while 11 studies reported using submaximal testing protocols. Cycle ergometry was the most used protocol, followed by treadmill and walk tests. Notably, complete descriptions of the test protocols to facilitate test replication were frequently absent. Conclusions Cycle ergometry is commonly used to assess CRF in people with MDD, but protocol details are lacking, making replication difficult. Efforts to standardize protocol descriptions are warranted.