Purpose: The evaluating ME may be valuable in order to the detection of muscle dysfunction and the assessment of any subsequent adaptations in response to training. This study aimed to compare the influence of 2 different exercise protocols: moderate continuous training (MCT) versus high intensity interval training (HIIT), as part of a cardiac rehabilitation program on ME values among coronary patients.
Methods: All patients underwent exercise testing with a cycle ergometer including analysis of exhaled gases. Patients were randomized on a one-to-one basis to either the MCT or the HIIT group. The mode of exercise training was a cycle ergometer with 40 minutes per sessions, 3 days per week (total of 24 sessions over 2 months). Selected CPET variables and ME measurement were recorded before and after the exercise program. ME (expressed as a percentage) was calculated during an incremental maximal cycling test at stages corresponding to VT1, VT2 and VO2peak.
Results: A total of 110 patients were included and studied (53 patients in MCT-group and 57 patients in HIIT-group). Both exercise programms significantly increase VO2peak with a higher increase in the HIIT group (2,96±2,33 ml/kg/min vs 3,88±2,40 ml/kg/min, for patients of the MCT and HIIT groups respectively, p<0,001). The ME at VO2peak and VT2 only significantly increased in the HIIT group (p<0,001).. At VT1, ME significantly increased in both groups, with a greater increase in the HIIT group (2,20±6,25 % vs 5,52±5,53 %, for patients of the MCT and HIIT groups respectively, p<0,001).
Conclusions: The application of HIIT to patients with chronic ischemic heart disease of low risk resulted in a greater improvement in VO2peak and in ME at VT1, than when MCT was applied. Moreover, only the application of HIIT brought about a significant increase in ME at VT2 and at VO2peak.