Left ventricular performance characteristics in trained and sedentary dogs.

Training effects on left ventricular (LV) performance were studied in 14 dogs. Nine had chronically implanted LV pressure transducers, five dogs had sham operations. Ventriculographic evaluation of LV function was performed initially in all animals.

Effect of endurance training on myocardial myosin adenosine triphosphatase activity of the dog.

Endurance exercise training has been found to enhance the functional capacity of the myocardium in several animal models. The sub-cellular phenomena accompanying the augmented function are yet to be explained. The present study sought to determine if the myosin ATPase activity of cardiac muscle increased as a result of endurance conditioning.