Effects of salicylates on exercise metabolism

¹ Department of Physical Medicine and Rehabilitation, College of Physicians and Surgeons, Columbia University; and Presbyterian Hospital, New York City

Some metabolic effects of salicylates were measured on ten normal young males steadily performing controlled moderate exercise after administration of acetyl salicylic acid (ASA). Dosages at a rate up to 4.8 g/day were administered over lengthening periods, the last dose 1–2 hr before walking on a power-driven treadmill in a temperature-controlled room. Oxygen consumption was measured, as were pulmonary ventilation, pulse rate, and blood lactic acid. While analysis of results indicated increase in resting O₂ consumption within 2 hr of the first dose, no modification of O₂ consumption of exercise appeared. Pulmonary ventilation was not increased after one dose, but did increase at rest, during exercise, and recovery after longer dosage; O₂ extraction from each unit of ventilation increased after one dose at rest and during exercise; the extraction ratio was still increased at rest after longer administration of ASA, but decreased during exercise and recovery. Increased ventilation was predominantly effected by increased depth of respiration rather than by changes in rate. Pulse rates were not changed and no significant effects on the cardiovascular system were discerned in this respect.