Effects of 4 weeks endurance training on cardiac left ventricular structure and function.

1. The effect of 4 weeks of moderate exercise training on cardiac left ventricular structure and function was examined by repeated echocardiographic/Doppler examination in 10 previously sedentary volunteers participating in a single blind, sedentary phase controlled, cross-over study. 2. Left ventricular internal diastolic diameter increased after 4 weeks of training from 4.98 to 5.11 cm with a further increase to 5.24 cm after 2 weeks of detraining (s.e.d. 0.05 cm, P < 0.01). These increases were still significant after adjustment for heart rate which fell from a pretraining average of 67.0-59.9 beats/min after 4 weeks of training. 3. There were no significant changes in systolic diameter or function and left ventricular wall thicknesses were unchanged during training, but were thinned after 2 weeks subsequent detraining. 4. The ratio of early to late transmitral filling velocity (E/A ratio) was significantly increased by training. Although E/A ratio was shown to be heart rate sensitive, training effects were still evident after adjustment for heart rate. 5. These changes in left ventricular volumes and function may contribute to the cardiovascular reflex changes previously shown to be produced by identical training programmes.

RCT Entities:   Population Interventions Outcomes