Interval and continuous aerobic exercise training similarly increase cardiac function and autonomic modulation in infarcted mice

Abstract

The present study aimed to compare the effects of moderate-intensity continuous and high-intensity interval exercise training (ET) on exercise tolerance, cardiac morphometry and function, hemodynamic, and car-diac autonomic modulation in myocardial infarcted mice. Wild-type mice (WT) were divided into four groups: sedentary WT (S); WT myo-cardium infarction sedentary (IS); WT myocardium infarction under-went to moderate-intensity continuous ET (MICT), and WT myocardium infarction underwent to high-intensity interval ET (MIIT). After 60 days of descending coronary artery ligation, moderate-intensity continuous ET consisted of running at 60% of maximum, while the high-intensity in-terval training consisted of eight sprints of 4 min at 80% of maximum and a 4-min recovery at 40% of maximum. Both exercises were per-formed 1 hr a day, 5 days a week, during 8 weeks. Results demonstrated that IS showed elevated exercise tolerance, as well as decreased he-modynamic and heart function, and autonomic control. On the other hand, both programs of ET were equally effective to increase all param-eters, without further differences between the groups. In conclusion, the results of the present study showed that myocardial infarction leads to damage in both investigated strains and the two types of physical ex-ercise attenuated the major impairments provoked by myocardial in-farction in exercise tolerance, cardiac structure, cardiac function, he-modynamic and cardiac autonomic modulation.