Influence of Carbohydrate on Immune Function Following 2 h Cycling

• Published in: Research in sports medicine Vol. 14; no. 3; pp. 225 - 237
• Main Authors: Nieman, David C., Henson, Dru A., Gojanovich, Greg, Mark Davis, J., Angela Murphy, E., Mayer, Eugene P., Pearce, Steven, Dumke, Charles L., Utter, Alan C., McAnulty, Steven R., McAnulty, Lisa S.
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis Group 01-09-2006
• Subjects: Adult; Bicycling - physiology; Dietary Carbohydrates - administration & dosage; Epinephrine - blood; exercise; Humans; Hydrocortisone - blood; Killer Cells, Natural - metabolism; Leukocyte Count; Lymphocyte Activation; lymphocytes; Male; Monocytes - metabolism; natural killer cells; Neutrophils - metabolism; Phytohemagglutinins - blood; T cells
• ISSN: 1543-8627; 1543-8635
• DOI: 10.1080/15438620600854793

The influence of carbohydrate compared with placebo ingestion on changes in immune cell counts and functions following 2 h intensive cycling was studied in 12 trained cyclists who functioned as their own controls. The subjects performed two tests 2 weeks apart where they cycled for 2 h at ∼64% Watts
max
while receiving 4 mL·kg
−1
·15 min
−1
carbohydrate (6%) (Cho) or placebo (Pla) beverages. Blood samples were collected 30 min preexercise, and immediately and 1 h postexercise. The samples were assayed for plasma cortisol and epinephrine, blood leukocyte subset counts, PHA-induced lymphocyte proliferation, and natural killer cell activity (NKCA). Compared with Pla ingestion, Cho attenuated exercise-induced changes in plasma cortisol, blood neutrophil, and monocyte counts, but not in total blood lymphocyte, T cell, and NK cell counts, PHA-induced lymphocyte proliferation, and NKCA. Thus despite a strong attenuating influence of carbohydrate ingestion on exercise-induced changes in plasma cortisol and blood neutrophil and monocyte counts, other immune measures related to lymphocyte subset counts, and function were unaffected.