Acute glutamine ingestion modulates lymphocytic responses to exhaustive exercise in the heat

The purpose of this study was to determine if acute intake of glutamine modulates homeostatic, hematologic, immune, and inflammatory responses to exhaustive exercise in the heat. Thirteen healthy untrained young men participated in this randomized, double-blind, placebo-controlled, crossover study. They served as their own control and completed two trials of treadmill exercise at 40% VO2max to exhaustion in a hot environment (38.0 ± 1.0 °C, 60.0 ± 5.0 % relative humidity, and 20.8% oxygen) following placebo (PLA) and glutamine (GLN) consumption. Heart rate, gastrointestinal temperature, forehead temperature, the rating of perceived exertion, and body weight were measured. Blood samples were collected pre- and post-exercise. After exhaustive exercise in the heat (PLA vs. GLN: 42.0 ± 9.5 vs. 39.6 ± 7.8 min, p>0.05), significant changes in homeostatic, hematologic, and immune parameters (elevated natural killer [NK] cells and neutrophils, and reduced CD4+/CD8+ ratio and CD19+ lymphocytes) were found in the control group due to the time effect (pThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author