Enrolled subjects ( n = 26 ; 7 women ; age 55 13 years ; ejection fraction 21 8 % ) completed a symptom-limited cardiopulmonary exercise test , the Kansas City Cardiomyopathy Questionnaire ( KCCQ ) , a 6-min walk test ( 6MW ) , and single-leg isokinetic strength test before 2:1 randomization to CR versus usual care .