Reliability and validity of physical fitness tests in people with mental disorders: A systematic review and meta-analysis

Background Several tests are available to assess the different components of physical fitness, including cardiorespiratory fitness, muscular strength, and flexibility. However, the reliability and validity of physical fitness tests in people with mental disorders has not been meta-analyzed. Aims To examine the reliability, concurrent, and convergent validity of physical fitness tests in people with mental disorders. Methods Studies evaluating the reliability, concurrent, and convergent validity of physical fitness tests in people with mental disorders were searched from major databases until January 20, 2020. Random-effects meta-analyses were performed pooling (1) reliability: test-retest correlations at two-time points, (2) convergent validity between submaximal tests and maximal protocols, or (3) concurrent validity between two submaximal tests. Associations are presented using r values and 95% confidence intervals. Methodological quality was assessed using the Quality Appraisal of Reliability Studies and the Critical Appraisal Tool. Results A total of 11 studies (N = 504; 34% females) were included. Reliability of the fitness tests, produced r values ranging from moderate (balance test-EUROFIT; [r = 0.75 (0.60-0.85); p = 0.0001]) to very strong (explosive leg power EUROFIT; [r = 0.96 (0.93-0.97); p = 0.0001]). Convergent validity between the 6-min walk test (6MWT) and submaximal cardiorespiratory tests was moderate (0.57 [0.26-0.77]; p = 0.0001). Concurrent validity between the 2-min walk test and 6MWT (r = 0.86 [0.39-0.97]; p = 0.0004) was strong. Conclusion The present study demonstrates that physical fitness tests are reliable and valid in people with mental disorders.