Evaluation of Doping Drugs by Treadmill Exercise in Dogs : I. Caffeine

Caffeine was examined for the effect upon the running performance on a treadmill in two trained dogs. A preliminary experiment was performed to find out running speeds at which the steady adaptation to exercise was broken up. Runs of 15-minute duration at speeds of 220 and 235 m/min in dog 1 and at a speed of 160 m/min in dog 2 (at a grade of 0% in both dogs) were determined to be employed in an experiment with caffeine. Caffeine was administered intravenously at single doses of 2.5, 5.0, and 7.5 mg/kg in the form of a mixture of caffeine and sodium benzoate. Runs were started 10 minutes after administration. Caffeine improved the running performance markedly at a strenuous work rate in dog 1, even at such a small dose as 2.5 mg/kg. On the contrary, it had an obscure performance-increasing effect on dog 2, even at such a large dose as 7.5 mg/kg, although the dog was placed on exercise at a much lower work rate than dog 1. The effect of caffeine would be evaluated only qualitatively, because of individual differences in this effect from dog to dog.