The Efficacy and Safety of Short-Term High- and Moderate-Intensity Interval Training in High-Risk Patients With Cardiovascular Disease

Purpose. This study aimed to investigate the efficacy and safety of short-term high- and moderate-intensity interval training (HIIT and MIIT) in high-risk patients with cardiovascular disease (CVD). Methods. We retrospectively recruited 161 high-risk patients with CVD that completed 4 weeks of exercise training in a cardiac rehabilitation clinic between February 2021 and June 2023; 80 patients underwent HIIT, and 81 underwent MIIT. The MIIT contained 4 sets×8 minutes at a rating of perceived exertion of 12 to 14 on the Borg scale of 6 to 20 with 2 minutes of rest between sets. The HIIT consisted of 20 cycles × 30 seconds at a rating of perceived exertion of 15 to 17 with 30 seconds of rest between cycles. Results. The median age was 54 years, and 65% were male. After 4 weeks, mean peak oxygen uptake ( ), at the anaerobic threshold, and oxygen pulse in HIIT versus MIIT increased by 2.6 versus 2.8 mL/kg/min, 1.7 versus 1.8 mL/kg/min, and 1.2 versus 0.9 mL/beat, respectively ( P <.001). The resting systolic and diastolic blood pressures both decreased after HIIT and MIIT (all P <.05). Few exercise-related mild adverse events (<1%) occurred during HIIT and MIIT, and compliance did not differ between groups ( P =.779). Conclusions. Our findings suggested that both HIIT and MIIT demonstrated improvements in , at anaerobic threshold, and oxygen pulse as well as reductions in blood pressure after 4 weeks of exercise training. No serious cardiac events occurred during the exercise training. Both HIIT and MIIT can be considered efficient and safe therapeutic methods for high-risk patients with CVD.