Blood volume, heart rate, and left ventricular ejection fraction changes in dogs before and after exercise during endurance training.

In Beagles (n = 5) after 7 weeks' endurance training, resting blood volume increased by an average of 13.1%. Resting heart rates were not significantly affected, but heart rates measured 2 minutes after exercise were significantly lower after the endurance training than before. Left ventricular ejection fractions determined by radionuclide angiography from 2 minutes after exercise showed no significant changes in response to a single exercise period or over the 50 days' training.