THE EFFECT OF EXERCISE UPON ACETOACETATE METABOLISM IN ATHLETES AND NON-ATHLETES

Thirteen male subjects at rest took sodium acetoacetate (200 ml., 0·4 M) by mouth and the subsequent changes in blood ketone bodies (acetoacetate plus 3-hydroxybutyrate), glucose, glycerol and free fatty acids were measured at intervals. Five of the subjects were in a state of athletic training and the others were not. Three of the trained subjects and six of the untrained were then given the same dose of acetoacetate during and again after a 1·5 hr run, and similar measurements made and compared with those during a run without giving acetoacetate. At rest, no difference appeared between the trained and the untrained; but after running, only the untrained showed significant ketosis and a decreased tolerance to acetotacetate. It is concluded that acetoacetate utilisation rises during exercise, and production is well matched to utilization in the athletically trained subject, but is excessive during and after exercise in the untrained subject.