Comparison of leucine kinetics in endurance-trained and sedentary humans
Date of Original Version
Whole body leucine kinetics was compared in endurance-trained athletes and sedentary controls matched for age, gender, and body weight. Kinetic studies were performed during 3 h of rest, 1 h of exercise (50% maximal oxygen consumption), and 2 h of recovery. When leucine kinetics were expressed both per unit of body weight and per unit of fat-free mass, both groups demonstrated an increase in leucine oxidation during exercise (P < 0.01). Trained athletes had a greater leucine rate of appearance during exercise and recovery compared with their sedentary counterparts (P < 0.05) and an increased leucine oxidation at all times on the basis of body weight (P < 0.05). However, all of these between-group differences were eliminated when leucine kinetics were corrected for fat-free tissue mass. Therefore, correction of leucine kinetics for fat-free mass may be important when cross- sectional investigations on humans are performed. Furthermore, leucine oxidation, when expressed relative to whole-body oxygen consumption during exercise, was similar between groups. It is concluded that there was no difference between endurance-trained and sedentary humans in whole body leucine kinetics during rest, exercise, or recovery when expressed per unit of fat-free tissue mass.
Journal of Applied Physiology
Lamont, Linda S., Arthur J. McCullough, and Satish C. Kalhan. "Comparison of leucine kinetics in endurance-trained and sedentary humans." Journal of Applied Physiology 86, 1 (1999): 320-325. doi:10.1152/jappl.19220.127.116.110.