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