Daily blood ketone body concentrations after acute exercise.
Post-exercise ketosis has been shown to occur in untrained subjects after 3--4 hours' walking, 1 1/2 hours' running or faster 20 minutes' cycling. Trained athletes appear to be resistant to post-exercise ketosis. The present study was undertaken to investigate whether post-exercise ketosis was related to the utilization of muscle glycogen during exercise. Fit and unfit subjects exercised on a bicycle ergometer for 15 minutes at their predicted maximal workload, or swam 90 m, with or without breath-holding, at 07h30. Blood lactate and ketone body levels were measured until 17h00. Although our subjects exercised more strenously than subjects in previous studies, neither the fit nor the unfit group developed ketone body levels which differed significantly from control day values after any of the three forms of exercise. Differences in food intake between fit and unfit, and between South African and Scottish subjects might explain these findings.
D000138:Acidosis / Q000209:etiology*; D000293:Adolescent; D000328:Adult; D006339:Heart Rate; D006801:Humans; D007101:Immersion; D007657:Ketone Bodies / Q000097:blood*; D007662:Ketosis / Q000209:etiology*; D007773:Lactates / Q000097:blood; D008297:Male; D005082:Physical Exertion; D010809:Physical Fitness; D013550:Swimming; D013997:Time Factors
D007657:Ketone Bodies; D007773:Lactates