Abstract P194: High Intensity Interval Training Protects the Heart

Abstract

Background: Human studies have shown high intensity interval training (HIIT) can have beneficial effects on the heart. The main goal of this study is to show 15 minutes of exercise with high intensity can has the same protective effects on the cardiovascular system as endurance training (ET) in healthy and diseased animals. Methods: For this study we used mouse (C57BL/6J) and rat (Wistar albino) models. We had three group of mice and rats: sedentary-control (CTRL), ET, and HIIT groups. First, 10-12 week old mice were treated with either ET or HIIT for 4 weeks. We performed heart ultrasonography, cardiomyocyte contractility, blood flow of the abdominal aorta and Western blot analysis for SOD-1, SOD-2, and citrate synthase to test cardiovascular differences between groups. Further, we used DHE staining, ATP production assay and O 2 - consumption kits. Second, 10-12 week old rats were treated with either ET of HIIT prior to ischemia/reperfusion injury on a Langendorff apparatus. Cardiodynamic data on dp/dt max, dp/dt min, SLVP, DLVP, heart rate, coronary flow and blood pressure were collected to observe differences between groups. Results: Our data reviled an increase in blood flow of mice abdominal aorta in both exercise groups compared to control but not between exercise groups itself (BF CTRL: 2218.7±10.0; BF ET: 2481.9±10.5; BF HIIT:2450.6±12.1). Ejection fraction was increased in HIIT compared to other groups (EF CTRL: 76.58±1.8; EF ET: 74.5±2.0 and EF HIIT: 84.83±2.4); Fractional shortening was increased in HIIT group compared to other groups (FS CTRL: 44.49±0.9; FS ET: 42.79±1.08; FS HIIT: 52.51±1.9). LIVDs was decreased in HIIT group compared to endurance, while in endurance was increased compare to control group (LIVDs CTRL: 1.11±0.3; LIVDs ET: 2.33±0.2; LIVDs HIIT: 1.4±0.2). DHE staining for ROS revealed no differences among groups. Conclusion: These findings indicate that HIIT have specific protective effects on the cardiovascular system compared to endurance training, even with possible higher heart contractility. People often cite the time as an excuse for lack of physical activity, however time is no longer an excuse.