Relationship between leucine oxidation and oxygen consumption during steady-state exercise
Date of Original Version
Purpose: The purpose of this study was to assess the relationship between whole-body leucine oxidation and oxygen consumption during steady-state exercise. Our hypothesis was that leucine oxidation will be responsive to increased whole-body energy needs. Methods: Sixteen healthy individuals (7 women and 9 men) were infused with a stable isotope of leucine and, for comparison purposes, lysine during 60 min of moderate-intensity exercise. Results: Leucine oxidation was increased (P < 0.05) and nonoxidative leucine disposal was decreased (P < 0.05), whereas leucine and lysine rate of appearance remained unchanged (P = NS) during exercise. Linear regression analysis indicated a modest relationship between leucine oxidation and steady-state oxygen consumption (R = 0.69; P < 0.003) during steady-state exercise. The coefficient of determination (R2 = 0.49) indicates that approximately half of the variance in whole-body leucine oxidation during exercise can be explained by whole-body oxygen consumption. Conclusion: In a statistically appropriate sample size of humans whose dietary intake was controlled, the whole-body rate of leucine oxidation during exercise was only partially influenced by energy demands.
Medicine and Science in Sports and Exercise
Lamont, L. S., A. J. McCullough, and S. C. Kalhan. "Relationship between leucine oxidation and oxygen consumption during steady-state exercise." Medicine and Science in Sports and Exercise 33, 2 (2001): 237-241. doi:10.1097/00005768-200102000-00011.