Optimization of high intensity interval exercise in coronary heart disease

High intensity interval training has been shown to be more effective than moderate intensity continuous training for improving maximal oxygen uptake (VO2max) in patients with coronary heart disease (CHD). However, no evidence supports the prescription of one specific protocol of high intensity interval exercise (HIIE) in this population. The purpose of this study was to compare the acute cardiopulmonary responses with four different single bouts of HIIE in order to identify the most optimal one in CHD patients. Nineteen stable CHD patients (17 males, 2 females, 65 +/- A 8 years) performed four different bouts of HIIE, all with exercise phases at 100% of maximal aerobic power (MAP), but which varied in interval duration (15 s for mode A and B and 60 s for mode C and D) and type of recovery (0% of MAP for modes A and C and 50% of MAP for modes B and D). A passive recovery phase resulted in a longer time to exhaustion compared to an active recovery phase, irrespective of the duration of the exercise and recovery periods (15 or 60 s, p < 0.05). Time to exhaustion also tended to be higher with mode A relative to mode C (p = 0.06). Despite differences in time to exhaustion between modes, time spent at a high percentage of VO2max was similar between HIIE modes except for less time spent above 90 and 95% of VO2max for mode C when compared with modes B and D. When considering perceived exertion, patient comfort and time spent above 80% of VO2max, mode A appeared to be the optimal HIIE session for these coronary patients.