Background Some survivors of critical illness experience poor physical recovery, but which patients experience the most compromise during recovery is unknown. Objective To identify factors associated with physical recovery by using the 6-minute walk test in adult survivors of critical illness 26 weeks after discharge from the hospital. Methods A total of 195 adult survivors of a critical illness were enrolled in a multicenter trial of physical rehabilitation after discharge from the hospital. The 6-minute walk test, the 36-Item Short Form Health Survey, and sleep rated on a 5-point scale were completed at weeks 1 and 26. Clinical and demographic data were obtained from patient records. Results A total of 145 patients completed the 26-week test. Of these, 94 (65%) increased the distance walked in 6 minutes by at least 75 m from the 1-week value and were therefore considered to have improved on the test. Factors associated with improvement included moderate to severe sleeping problems in week 1, moderate to vigorous exercise in week 26, and higher vitality in week 26. Conversely, respiratory problems and higher social functioning in week 1 were associated with less improvement in the distance walked. Conclusion Multiple factors are associated with physical recovery after critical illness. Interventions to target multidimensional aspects of recovery such as sleep and exercise may result in improved physical function after critical illness.