Arterial Concentrations of Free Fatty Acids and Free Amino Acids in Healthy Human Individuals at Rest and at Different Work Loads

Abstract
The influence of physical work on the arterial plasma levels of free amino acids and free fatty acids was studied in 13 healthy individuals in a postabsorptive state. During work the total amino nitrogen level increased. Among the individual amino acid-alanine increased markedly. After a slight fall in the plasma free fatty acid level during the first minutes of exercise, the free fatty acids increased to the pre-exercise level after about 15 minutes of exercise. The percentage of stearic acid in the free fatty acid fraction decreased markedly during work. The significance of these findings for muscle metabolism during work is discussed.