Effect of resistance exercise on cardiac perturbations and systolic performance: A cross-over randomized trial comparing volumes and techniques.

This study investigated the magnitude and time-course of resistance exercise (RE) technique induced transient cardiac perturbations. Twenty-four participants were assigned to one of four arms: sets to failure or non-failure with 8-10 repetition maximum (RM), and sets to failure or non-failure with 15RM. Echocardiographic and blood pressure (BP) data were recorded at baseline and 30 min, 6 h and 24 h post-exercise. In all groups end-systolic circumferential wall stress (cESS), and ratio of transmitral inflow velocities (E/A) were significantly decreased while posterior wall thickness (PWT), global circumferential strain (GCS), GCS strain rate (GCSR), global longitudinal strain rate (GLSR), and stroke volume (SV) were significantly increased for up to 6 h of follow-up. In the 15RM groups, left ventricular (LV) mass and interventricular septal thickness (IVST) were significantly increased, and left atrial (LA) area was significantly decreased ( p  < 0.05) compared to the 8-10 RM groups. In the 15RM groups, RE decreased global longitudinal strain (GLS) and increased ejection fraction (EF) (p<0.01). After RE, transient cardiac perturbations, the reduction in LA compliance, and the improvement in LV myofibril geometry were volume dependent and influenced more by sets to failure technique. RE increased GCS and reduced the afterload, thus helping to preserve SV and EF.