The influence of low-intensity resistance training versus high-intensity resistance training on left ventricular structure and function of healthy adolescent boys using Echocardiography

The study on the influence of different protocol of resistance training on left ventricular of adolescent boys dose have its limitation. The aim of this study was to determine the influence of low-intensity resistance training versus high-intensity resistance training on left ventricular structure and function of healthy adolescent boys by echocardiography. Twenty-four subjects volunteers، 15 to 18 years old were randomly assigned to three groups in the eight-member low-intensity resistance training (40% to 60% maximum strength)، high-intensity resistance training (70% to 90% maximum strength) and control group. Protocol training was conducted 8 weeks، 3 sessions. Variables were measured using one and two-dimensional echocardiography at rest and special formulas. In the post-test to pre-test، in low-intensity resistance training group means values، left ventricular posterior wall thickness at end-systole (P=0. 028) and resting heart rate (P=0. 017) showed significant increase and decrease respectively. In post-test، it was shown a significant increase means values left ventricular posterior wall thickness at end-systole and left ventricular mass index in low-intensity resistance training group than high-intensity resistance training group (P=0. 007 and P=0. 005 respectively) and control group (P=0. 005 and P=0. 0015 respectively) and mean value left ventricular mass in low-intensity resistance training group than high-intensity resistance training group (P<0. 007). Low-intensity resistance training than high-intensity resistance training in healthy adolescent boys caused some changes in left ventricular structure and function، probably these changes were associated with increased volume and pressure load.