The dynamics of plasma free fatty acid metabolism during exercise*

Abstract

Palmitic acid-1-C14 was given intravenously to volunteer subjects before, and toward the end of, 35–45 min of exercise. The fractional turnover rate and total turnover rates for plasma free fatty acids were greater during exercise. The concentration of free fatty acids in the plasma fell at the beginning of exercise, then rose and exceeded the resting levels. Immediately after exercise, there was a further abrupt rise and then another decline. The results indicate that exercise accelerates the efflux of plasma free fatty acids and then, secondarily, increases mobilization of free fatty acids from depots.