Impact of training methods and patient characteristics on exercise capacity in patients in cardiovascular rehabilitation

AIM: We aimed to identify patient characteristics and comorbidities that correlate with the initial exercise capacity of cardiac rehabilitation (CR) patients and to study the significance of patient characteristics, comorbidities and training methods for training achievements and final fitness of CR patients.

METHODS: We studied 557 consecutive patients (51.7 ± 6.9 years; 87.9% men) admitted to a three-week in-patient CR. Cardiopulmonary exercise testing (CPX) was performed at discharge. Exercise capacity (watts) at entry, gain in training volume and final physical fitness (assessed by peak O₂ utilization (VO₂peak) were analysed using analysis of covariance (ANCOVA) models.

RESULTS: Mean training intensity was 90.7 ± 9.7% of maximum heart rate (81% continuous/19% interval training, 64% additional strength training). A total of 12.2 ± 2.6 bicycle exercise training sessions were performed. Increase of training volume by an average of more than 100% was achieved (difference end/beginning of CR: 784 ± 623 watts × min). In the multivariate model the gain in training volume was significantly associated with smoking, age and exercise capacity at entry of CR. The physical fitness level achieved at discharge from CR as assessed by VO₂peak was mainly dependent on age, but also on various factors related to training, namely exercise capacity at entry, increase of training volume and training method.

CONCLUSION: CR patients were trained in line with current guidelines with moderate-to-high intensity and reached a considerable increase of their training volume. The physical fitness level achieved at discharge from CR depended on various factors associated with training, which supports the recommendation that CR should be offered to all cardiac patients.