Aerobic and anaerobic metabolism in exercising dogs

Abstract

For an analysis of the energy expenditure as related to the work performance in exercising dogs, the O2 consumption and the lactic acid production were determined at rest and during running on a treadmill at varying speeds (from 4 to 16 km/hr) and inclines (from 0 to +20%). The incline being constant, the O2 consumption was found to increase linearly with the speed. Although the maximum O2 intake probably could not be reached, the highest value measured, 100 ml O2/kg min, was about twice the average maximum O2 intake value for untrained men. The lactic acid production became detectable as the metabolic rate reached about 280 cal/kg min and increased at higher metabolic levels. The contribution of the anaerobic metabolism to the increase of the total metabolic rate due to exercise attained about 5% at the highest metabolic rate that could be measured, 580 cal/kg min The energy cost of running per kilogram body weight was found to be the same as in man for running on the level, 1.0 kcal/kg min; it increased more than in man in uphill running. The efficiency of running, as for man, was found to be independent of the speed. O2 consumption during running; lactic acid production during running; pyruvic acid production during running; energy cost and mechanical efficiency Submitted on July 15, 1963