Title

Relationship between leucine oxidation and oxygen consumption during steady-state exercise

Document Type

Article

Date of Original Version

1-1-2001

Abstract

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.

Publication Title

Medicine and Science in Sports and Exercise

Volume

33

Issue

2

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