Medicine & Science in Sports & Exercise. 24(12):1353–1358, DECEMBER 1992
PMID: 1470018
Issn Print: 0195-9131
Publication Date: December 1992
Plasma amino acid concentrations in the overtraining syndrome: possible effects on the immune system
MARK PARRY-BILLINGS;RICHARD BUDGETT;YIANNIS KOUTEDAKIS;EVA BLOMSTRAND;STEVEN BROOKS;CLYDE WILLIAMS;PHILIP CALDER;SIAN PILLING;ROBERT BAIGRIE;ERIC NEWSHOLME;
+ Author Information
Cellular Nutrition Research Group, Department of Biochemistry, University of Oxford, U.K.; British Olympic Medical Centre, Northwick Park Hospital, Harrow, U.K.; Department of Physical Education and Sports Science, University of Loughborough, U.K.; and Nuffield Department of Surgery, John Radcliffe Hospital, Oxford, U.K.
Abstract
PARRY-BILLINGS, M., R. BUDGETT, Y. KOUTEDAKIS, E. BLOMSTRAND, S. BROOKS, C. WILLIAMS, P. C. CALDER, S. PILLING, R. BAIGRIE, and E. A. NEWSHOLME. Plasma amino acid concentrations in the overtraining syndrome: possible effects on the immune system. Med. Sci. Sports Exerc., Vol. 24, No. 12, pp. 1353–1358, 1992. Overtraining and long-term exercise are associated with an impairment of immune function. We provide evidence in support of the hypothesis that the supply of glutamine, a key fuel for cells of the immune system, is impaired in these conditions and that this may contribute to immunosuppression. Plasma glutamine concentration was decreased in overtrained athletes and after long-term exercise (marathon race) and was increased after short-term, high intensity exercise (sprinting). Branched chain amino acid supplementation during long-term exercise was shown to prevent this decrease in the plasma glutamine level. Overtraining was without effect on the rate of T-lymphocyte proliferation in vitro or on the plasma levels of interleukin-1 and −6, suggesting that immune function is not impaired in this condition. Given the proposed importance of glutamine for cells of the immune system, it is concluded that the decrease in plasma glutamine concentration in overtraining and following long-term exercise, and not an intrinsic defect in T lymphocyte function, may contribute to the immune deficiency reported in these conditions.
