Both moderate-intensity continuous and high-intensity interval aerobic training promoted beneficial adaptations to cardiac morphology, function, and mechanical properties in hypertensive rats.
Does moderate-intensity continuous or high-intensity interval aerobic training improve cardiac function and cardiomyocyte mechanical properties in spontaneously hypertensive rats?
Both moderate-intensity continuous and high-intensity interval aerobic training promote beneficial adaptations to cardiac morphology, function, and cardiomyocyte mechanical properties in spontaneously hypertensive rats.
The aim of this study was to verify the effects of moderate-intensity continuous (MICT) and high-intensity interval (HIIT) aerobic training on cardiac morphology and function and the mechanical properties of single cardiomyocytes in spontaneously hypertensive rats (SHR) in the compensated phase of hypertension. Sixteen-week-old male SHR and normotensive Wistar (WIS) rats were allocated to six groups of six animals each: SHR CONT or WIS CONT (control); SHR MICT or WIS MICT (underwent MICT, 30 min/day, five days per week for eight weeks); and SHR HIIT or WIS HIIT (underwent HIIT, 30 min/day, five days per week for eight weeks). Total exercise time until fatigue and maximum running speed were determined using a maximal running test before and after the experimental period. Systolic (SAP), diastolic (DAP), and mean (MAP) blood pressures were measured using tail plethysmography before and after the experimental period. Echocardiographic evaluations were performed at the end of the experimental period. The rats were euthanized after in vivo assessments, and left ventricular myocytes were isolated to evaluate global intracellular Ca 2+ transient (Ca 2+ i ) and contractile function. Cellular measurements were performed at basal temperature (~37°C) at 3, 5, and 7 Hz. The results showed that both training programs increased total exercise time until fatigue and, consequently, maximum running speed. In hypertensive rats, MICT decreased SAP, DAP, MAP, interventricular septal thickness during systole and diastole, and the contraction amplitude at 5 Hz. HIIT increased heart weight and left ventricular wall thickness during systole and diastole and reduced SAP, MAP, and the time to peak Ca 2+ i at all pacing frequencies. In conclusion, both aerobic training protocols promoted beneficial adaptations to cardiac morphology, function, and mechanical properties of single cardiomyocytes in SHR.
Suarez et al. (Tue,) conducted a other in Hypertension (n=36). Moderate-intensity continuous (MICT) and high-intensity interval (HIIT) aerobic training vs. Control was evaluated on Cardiac morphology, function, and mechanical properties of single cardiomyocytes. Both moderate-intensity continuous and high-intensity interval aerobic training promoted beneficial adaptations to cardiac morphology, function, and mechanical properties in hypertensive rats.