Effects of high-intensity interval versus continuous exercise training on post-exercise heart rate recovery in coronary heart-disease patients.

BACKGROUND: Heart rate recovery (HRR) has been considered a prognostic and mortality indicator in both healthy and coronary patients. Physical exercise prescription has shown improvements in VO2 peak and HRR, but most of the studies have been carried out applying continuous training at a moderate intensity, being very limited the use of protocols of high intensity interval training in coronary patients. We aimed to compare the effects of a moderate continuous training (MCT) versus a high intensity interval training (HIIT) programme on VO2 peak and HRR.

METHODS: Seventy three coronary patients were assigned to either HIIT or MCT groups for 8weeks. Incremental exercise tests in a cycloergometer were performed to obtain VO2 peak data and heart rate was monitored during and after the exercise test to obtain heart rate recovery data.

RESULTS: Both exercise programmes significantly increase VO2 peak with a higher increase in the HIIT group (HIIT: 4.5±4.46ml/kg/min vs MCT: 2.46±3.57ml/kg/min; p=0.039). High intensity interval training resulted in a significantly increase in HRR at the first and second minute of the recovery phase (15,44±7,04 vs 21,22±6,62, p<0,0001 and 23,73±9,64 vs 31,52±8,02, p<0,0001, respectively).

CONCLUSIONS: The results of our research show that the application of HIIT to patients with chronic ischemic heart disease of low risk resulted in an improvement in VO2 peak, and also improvements in post-exercise heart-rate recovery, compared with continuous training.