Effects of high-intensity interval training in a three-week cardiovascular rehabilitation: a randomized controlled trial

Objective: The aim of this study was to assess the benefit of using high-intensity interval training for cardiovascular patients undergoing outpatient rehabilitation in a standard short-term (three-week) program in Germany. Design: This is a randomized controlled trial (RCT). Setting: This study was conducted at Cardiowell (Wuppertal, Germany), an outpatient rehabilitation center. Intervention: Patients underwent the typical three-week German outpatient rehabilitation program using either moderate continuous training (i.e. the standard training program) or high-intensity interval training. Main measures: A total of 50 patients of an outpatient rehabilitation center were randomized into two groups. The control group underwent the standard rehabilitation protocol that applied moderate continuous training, and the intervention group trained according to a high-intensity interval protocol. Patients trained on a bicycle ergometer. Peak power output, oxygen uptake parameters, heart frequencies, and blood pressure were compared at the beginning and at the end of the rehabilitation program. Results: After three weeks, the intervention group had improved to a significantly greater extent in maximal performance parameters than the control group: the peak power output (20.9 (±14.1) W; control 8.8 (±10.4) W), maximum oxygen uptake (0.33 (±0.33) L/min; control 0.05 (±0.29) L/min)), relative maximum oxygen uptake (3.4 (±4.2) mL/kg/min; control 0.9 (±3.1) mL/kg/min), and O2 pulse (1.8 (±2.2) mL/heart beat; control 0.35 (±1.7) mL/heart beat). Conclusion: The implementation of high-intensity interval training during a typical three-week German cardiac rehabilitation has the power to increase the outcome for the patients.