Background: Past research has compared the effects of moderate-intensity continuous training (MCT) versus high-intensity interval training (HIIT) in phase 2 cardiac rehabilitation patients, but with conflicting results. Therefore, the purpose of this study was to evaluate if HIIT leads to greater improvements in functional capacity when compared with MCT in a group of phase 2 cardiac rehabilitation patients.
Methods: Eighteen patients in a phase 2 cardiac rehabilitation program completed precardiopulmonary and postcardiopulmonary exercise tests, a 12-min walk test (12MWT), and resting blood pressure (BP). After 2 weeks of run-in, patients were randomly assigned to 10 weeks of HIIT (alternating periods of 80%–90% heart rate [HR] reserve and 60%–70% HR reserve) or MCT (60%–80% HR reserve) exercise group. Changes in VO2 peak, 12MWT distance, and BP (mm Hg) were analyzed by independent t test.
Results: The average patient was 65 years old, 1.75 m tall, and overweight. VO2 peak values improved for individuals in both exercise modalities. There was no significant difference between the exercise groups (P = 0.174). In addition, both groups improved their 12MWT distance, resting systolic, and diastolic BP (DBP), with no significant difference in improvements between the 2 exercise groups.
Conclusion: In this study, HIIT was not more effective than MCT for improving functional capacity in a group of phase 2 cardiac rehabilitation patients. However, since HIIT was equally effective compared with MCT in several measures, it provides another option for exercise prescription to the traditional prescription for this population.