Development and validation of cardiorespiratory fitness prediction equations from 6-minute walk test: the Coronary Artery Risk Development in Adults (CARDIA) study
Year: 2026
Type: article
Abstract: BACKGROUND: Assessing maximal oxygen consumption (VO2max), the gold standard for assessing cardiorespiratory fitness, is often impractical in large-scale studies. We derived sex-specific VO2 max and graded exercise test duration (GXTd) prediction equations from 6-minute walk test (6MWT) performance. METHODS: Data were from 564 Coronary Artery Risk Development in Young Adults (CARDIA) participants (mean age: 61.5 years; 58% women; 40% Black) who completed the 6MWT and symptom-limited modified Balke treadmill graded exercise test at the Year 35 (2021-2022) follow-up exam. Sex-stratified samples were randomly split (2/3 for training, 1/3 for testing) to derive and evaluate prediction equations. Stepwise linear regression identified predictors of VO2max and GXTd from 6MWT distance. Sex-specific VO2max CARDIA equations were compared with Burr and FRIEND equations. Models' accuracies were evaluated by comparing the predicted values to measured values using Student's t-test and Pearson correlation coefficients (r). Bland-Altman plots used to evaluate agreement between measured and predicted values. RESULTS: Sex-specific VO2max CARDIA equations explained 53% and 57% of the variance in men and women, respectively, with strong correlations between measured and predicted values (r = 0.73 and 0.78). The Burr and FRIEND equations showed larger biases and weaker correlations compared with the CARDIA equations. The GXTd equations explained 59% and 62% of the variance in men and women, with strong correlations (r = 0.71 and 0.72) and no significant mean differences between observed and predicted. CONCLUSIONS: The CARDIA prediction equations for VO2max and GXTd from 6MWT enhance accuracy and accessibility, providing a practical tool for large-scale studies and clinical assessments, particularly in aging populations.
Institutions: University of Alabama at Birmingham, Duke University, Durham VA Medical Center, The University of Texas Health Science Center at Houston, Johns Hopkins University, University of Minnesota, Northwestern University, Kaiser Permanente, Kaiser Permanente Northern California, University of North Carolina at Chapel Hill
Language: English
Subfield: Complementary and alternative medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,408
Awards: G1706281457, G3558984962
OpenAlex ID: W7128957465
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