High-intensity interval training (HIIT) is considered to be a potent stimulus for enhancing cardiorespiratory fitness (VO2) in patients with coronary artery disease (CAD). However, the feasibility and efficacy of HIIT have not been well-studied. This study aims to compare moderate-intensity continuous training (MICT) with HIIT) in patients with CAD.
This randomized, single-center study included a total of 93 participants with proven CAD who underwent supervised training in a private cardiac rehabilitation program and subsequent home-based training. The patients were randomized in a 1:1 ratio to a 4×4-minute HIIT program (n=46) or a 40-minute MICT program (usual care, n=47). The primary outcome of the study was a change in cardiorespiratory fitness measured by VO2 peak levels.
At 4 weeks, 86 patients completed the study (43 in each group). At 12 months, 69 of 93 patients completed the testing; 32 in the HIIT group and 37 in the MICT group. After 4 weeks, patients in the HIIT group had a 10% improvement in the VO2 peak levels, compared with 4% in the MICT group. The improvements in the two groups after 12 months were 10% and 7%, respectively.
The research concluded that patients with CAD who underwent HIIT experienced greater improvements in VO2 peak levels, as compared with those who underwent MICT.