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. 1998 Mar;32(1):25–33. doi: 10.1136/bjsm.32.1.25

Contrasting plasma free amino acid patterns in elite athletes: association with fatigue and infection

K J Kingsbury, L Kay, M Hjelm
PMCID: PMC1756055  PMID: 9562160

Abstract

AIM: There is little information on the plasma free amino acid patterns of elite athletes against which fatigue and nutrition can be considered. Therefore the aim was to include analysis of this pattern in the medical screening of elite athletes during both especially intense and light training periods. METHODS: Plasma amino acid analysis was undertaken in three situations. (1) A medical screening service was offered to elite athletes during an intense training period before the 1992 Olympics. Screening included a blood haematological/biochemical profile and a microbial screen in athletes who presented with infection. The athletes were divided into three groups who differed in training fatigue and were considered separately. Group A (21 track and field athletes) had no lasting fatigue; group B (12 judo competitors) reported heavy fatigue at night but recovered overnight to continue training; group C (18 track and field athletes, one rower) had chronic fatigue and had been unable to train normally for at least several weeks. (2) Athletes from each group were further screened during a post- Olympic light training period. (3) Athletes who still had low amino acid levels during the light training period were reanalysed after three weeks of additional protein intake. RESULTS: (1) The pre-Olympics amino acid patterns were as follows. Group A had a normal amino acid pattern (glutamine 554 (25.2) micromol/l, histidine 79 (6.1) micromol/l, total amino acids 2839 (92.1) micromol/l); all results are means (SEM). By comparison, both groups B and C had decreased plasma glutamine (average 33%; p<0.001) with, especially in group B, decreased histidine, glucogenic, ketogenic, and branched chain amino acids (p<0.05 to p<0.001). None in group A, one in group B, but ten athletes in group C presented with infection: all 11 athletes had plasma glutamine levels of less than 450 micromol/l. No intergroup differences in haematological or other blood biochemical parameters, apart from a lower plasma creatine kinase activity in group C than in group B (p<0.05) and a low neutrophil to lymphocyte ratio in the athletes with viral infections (1.2 (0.17)), were found. (2) During post-Olympic light training, group A showed no significant amino acid changes. In contrast, group B recovered normal amino acid levels (glutamine 528 (41.4) micromol/l, histidine 76 (5.3) micromol/l, and total amino acids 2772 (165) micromol/l) (p<0.05 to p<0.001) to give a pattern comparable with that of group A, whereas, in group C, valine and threonine had increased (p<0.05), but glutamine (441 (24.5) micromol/l) and histidine (58 (5.3) micromol/l) remained low. Thus none in group A, two in group B, but ten (53%) in group C still had plasma glutamine levels below 450 micromol/l, including eight of the 11 athletes who had presented with infection. (3) With the additional protein intake, virtually all persisting low glutamine levels increased to above 500 micromol/l. Plasma glutamine rose to 592 (35.1) micromol/l and histidine to 86 (6.0) micromol/l. Total amino acids increased to 2761 (128) micromol/l (p<0.05 to p<0.001) and the amino acid pattern normalised. Six of the ten athletes on this protein intake returned to increased training within the three weeks. CONCLUSION: Analysis of these results provided contrasting plasma amino acid patterns: (a) a normal pattern in those without lasting fatigue; (b) marked but temporary changes in those with acute fatigue; (c) a persistent decrease in plasma amino acids, mainly glutamine, in those with chronic fatigue and infection, for which an inadequate protein intake appeared to be a factor. 




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Selected References

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  1. Ahlborg G., Felig P., Hagenfeldt L., Hendler R., Wahren J. Substrate turnover during prolonged exercise in man. Splanchnic and leg metabolism of glucose, free fatty acids, and amino acids. J Clin Invest. 1974 Apr;53(4):1080–1090. doi: 10.1172/JCI107645. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Askanazi J., Carpentier Y. A., Michelsen C. B., Elwyn D. H., Furst P., Kantrowitz L. R., Gump F. E., Kinney J. M. Muscle and plasma amino acids following injury. Influence of intercurrent infection. Ann Surg. 1980 Jul;192(1):78–85. doi: 10.1097/00000658-198007000-00014. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bergström J., Fürst P., Hultman E. Free amino acids in muscle tissue and plasma during exercise in man. Clin Physiol. 1985 Apr;5(2):155–160. doi: 10.1111/j.1475-097x.1985.tb00591.x. [DOI] [PubMed] [Google Scholar]
  4. Bergström J., Fürst P., Vinnars E. Effect of a test meal, without and with protein, on muscle and plasma free amino acids. Clin Sci (Lond) 1990 Oct;79(4):331–337. doi: 10.1042/cs0790331. [DOI] [PubMed] [Google Scholar]
  5. Blomstrand E., Hassmén P., Ekblom B., Newsholme E. A. Administration of branched-chain amino acids during sustained exercise--effects on performance and on plasma concentration of some amino acids. Eur J Appl Physiol Occup Physiol. 1991;63(2):83–88. doi: 10.1007/BF00235174. [DOI] [PubMed] [Google Scholar]
  6. Bodwell C. E., Schuster E. M., Kyle E., Brooks B., Womack M., Steele P., Ahrens R. Obligatory urinary and fecal nitrogen losses in young women, older men, and young men and the factorial estimation of adult human protein requirements. Am J Clin Nutr. 1979 Dec;32(12):2450–2459. doi: 10.1093/ajcn/32.12.2450. [DOI] [PubMed] [Google Scholar]
  7. Burke D. J., Alverdy J. C., Aoys E., Moss G. S. Glutamine-supplemented total parenteral nutrition improves gut immune function. Arch Surg. 1989 Dec;124(12):1396–1399. doi: 10.1001/archsurg.1989.01410120042009. [DOI] [PubMed] [Google Scholar]
  8. Castell L. M., Poortmans J. R., Leclercq R., Brasseur M., Duchateau J., Newsholme E. A. Some aspects of the acute phase response after a marathon race, and the effects of glutamine supplementation. Eur J Appl Physiol Occup Physiol. 1997;75(1):47–53. doi: 10.1007/s004210050125. [DOI] [PubMed] [Google Scholar]
  9. Castell L. M., Poortmans J. R., Newsholme E. A. Does glutamine have a role in reducing infections in athletes? Eur J Appl Physiol Occup Physiol. 1996;73(5):488–490. doi: 10.1007/BF00334429. [DOI] [PubMed] [Google Scholar]
  10. Crawford J., Cohen H. J. The essential role of L-glutamine in lymphocyte differentiation in vitro. J Cell Physiol. 1985 Aug;124(2):275–282. doi: 10.1002/jcp.1041240216. [DOI] [PubMed] [Google Scholar]
  11. Curthoys N. P., Watford M. Regulation of glutaminase activity and glutamine metabolism. Annu Rev Nutr. 1995;15:133–159. doi: 10.1146/annurev.nu.15.070195.001025. [DOI] [PubMed] [Google Scholar]
  12. Davey J. F., Ersser R. S. Amino acid analysis of physiological fluids by high-performance liquid chromatography with phenylisothiocyanate derivatization and comparison with ion-exchange chromatography. J Chromatogr. 1990 Jun 8;528(1):9–23. doi: 10.1016/s0378-4347(00)82358-0. [DOI] [PubMed] [Google Scholar]
  13. Durnin J. V., Womersley J. Body fat assessed from total body density and its estimation from skinfold thickness: measurements on 481 men and women aged from 16 to 72 years. Br J Nutr. 1974 Jul;32(1):77–97. doi: 10.1079/bjn19740060. [DOI] [PubMed] [Google Scholar]
  14. Décombaz J., Reinhardt P., Anantharaman K., von Glutz G., Poortmans J. R. Biochemical changes in a 100 km run: free amino acids, urea, and creatinine. Eur J Appl Physiol Occup Physiol. 1979 Apr 12;41(1):61–72. doi: 10.1007/BF00424469. [DOI] [PubMed] [Google Scholar]
  15. Elia M., Neale G., Livesey G. Alanine and glutamine release from the human forearm: effects of glucose administration. Clin Sci (Lond) 1985 Aug;69(2):123–133. doi: 10.1042/cs0690123. [DOI] [PubMed] [Google Scholar]
  16. Garza C., Scrimshaw N. S., Young V. R. Human protein requirements: a long-term metabolic nitrogen balance study in young men to evaulate the 1973 FAO/WHO safe level of egg protein intake. J Nutr. 1977 Feb;107(2):335–352. doi: 10.1093/jn/107.2.335. [DOI] [PubMed] [Google Scholar]
  17. Graham T. E., Saltin B. Estimation of the mitochondrial redox state in human skeletal muscle during exercise. J Appl Physiol (1985) 1989 Feb;66(2):561–566. doi: 10.1152/jappl.1989.66.2.561. [DOI] [PubMed] [Google Scholar]
  18. Hack V., Weiss C., Friedmann B., Suttner S., Schykowski M., Erbe N., Benner A., Bärtsch P., Dröge W. Decreased plasma glutamine level and CD4+ T cell number in response to 8 wk of anaerobic training. Am J Physiol. 1997 May;272(5 Pt 1):E788–E795. doi: 10.1152/ajpendo.1997.272.5.E788. [DOI] [PubMed] [Google Scholar]
  19. Haralambie G., Berg A. Serum urea and amino nitrogen changes with exercise duration. Eur J Appl Physiol Occup Physiol. 1976 Dec 6;36(1):39–48. doi: 10.1007/BF00421632. [DOI] [PubMed] [Google Scholar]
  20. Hood D. A., Terjung R. L. Amino acid metabolism during exercise and following endurance training. Sports Med. 1990 Jan;9(1):23–35. doi: 10.2165/00007256-199009010-00003. [DOI] [PubMed] [Google Scholar]
  21. Keast D., Arstein D., Harper W., Fry R. W., Morton A. R. Depression of plasma glutamine concentration after exercise stress and its possible influence on the immune system. Med J Aust. 1995 Jan 2;162(1):15–18. doi: 10.5694/j.1326-5377.1995.tb138403.x. [DOI] [PubMed] [Google Scholar]
  22. Kopple J. D., Swendseid M. E. Evidence that histidine is an essential amino acid in normal and chronically uremic man. J Clin Invest. 1975 May;55(5):881–891. doi: 10.1172/JCI108016. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Lemon P. W., Yarasheski K. E., Dolny D. G. The importance of protein for athletes. Sports Med. 1984 Nov-Dec;1(6):474–484. doi: 10.2165/00007256-198401060-00006. [DOI] [PubMed] [Google Scholar]
  24. Mackinnon L. T., Hooper S. L. Plasma glutamine and upper respiratory tract infection during intensified training in swimmers. Med Sci Sports Exerc. 1996 Mar;28(3):285–290. doi: 10.1097/00005768-199603000-00003. [DOI] [PubMed] [Google Scholar]
  25. Nieman D. C., Johanssen L. M., Lee J. W., Arabatzis K. Infectious episodes in runners before and after the Los Angeles Marathon. J Sports Med Phys Fitness. 1990 Sep;30(3):316–328. [PubMed] [Google Scholar]
  26. Parry-Billings M., Budgett R., Koutedakis Y., Blomstrand E., Brooks S., Williams C., Calder P. C., Pilling S., Baigrie R., Newsholme E. A. Plasma amino acid concentrations in the overtraining syndrome: possible effects on the immune system. Med Sci Sports Exerc. 1992 Dec;24(12):1353–1358. [PubMed] [Google Scholar]
  27. Peters E. M., Bateman E. D. Ultramarathon running and upper respiratory tract infections. An epidemiological survey. S Afr Med J. 1983 Oct 1;64(15):582–584. [PubMed] [Google Scholar]
  28. Petersson B., Vinnars E., Waller S. O., Wernerman J. Long-term changes in muscle free amino acid levels after elective abdominal surgery. Br J Surg. 1992 Mar;79(3):212–216. doi: 10.1002/bjs.1800790307. [DOI] [PubMed] [Google Scholar]
  29. Petersson B., Wernerman J., Waller S. O., von der Decken A., Vinnars E. Elective abdominal surgery depresses muscle protein synthesis and increases subjective fatigue: effects lasting more than 30 days. Br J Surg. 1990 Jul;77(7):796–800. doi: 10.1002/bjs.1800770725. [DOI] [PubMed] [Google Scholar]
  30. Rammohan M., Juan D. Effects of a low calorie, low protein diet on nutritional parameters, and routine laboratory values in nonobese young and elderly subjects. J Am Coll Nutr. 1989 Dec;8(6):545–553. doi: 10.1080/07315724.1989.10720325. [DOI] [PubMed] [Google Scholar]
  31. Rennie M. J., Edwards R. H., Krywawych S., Davies C. T., Halliday D., Waterlow J. C., Millward D. J. Effect of exercise on protein turnover in man. Clin Sci (Lond) 1981 Nov;61(5):627–639. doi: 10.1042/cs0610627. [DOI] [PubMed] [Google Scholar]
  32. Rohde T., MacLean D. A., Hartkopp A., Pedersen B. K. The immune system and serum glutamine during a triathlon. Eur J Appl Physiol Occup Physiol. 1996;74(5):428–434. doi: 10.1007/BF02337723. [DOI] [PubMed] [Google Scholar]
  33. Roth E., Funovics J., Mühlbacher F., Schemper M., Mauritz W., Sporn P., Fritsch A. Metabolic disorders in severe abdominal sepsis: glutamine deficiency in skeletal muscle. Clin Nutr. 1982 Mar;1(1):25–41. doi: 10.1016/0261-5614(82)90004-8. [DOI] [PubMed] [Google Scholar]
  34. Rowbottom D. G., Keast D., Goodman C., Morton A. R. The haematological, biochemical and immunological profile of athletes suffering from the overtraining syndrome. Eur J Appl Physiol Occup Physiol. 1995;70(6):502–509. doi: 10.1007/BF00634379. [DOI] [PubMed] [Google Scholar]
  35. Souba W. W., Klimberg V. S., Plumley D. A., Salloum R. M., Flynn T. C., Bland K. I., Copeland E. M., 3rd The role of glutamine in maintaining a healthy gut and supporting the metabolic response to injury and infection. J Surg Res. 1990 Apr;48(4):383–391. doi: 10.1016/0022-4804(90)90080-l. [DOI] [PubMed] [Google Scholar]
  36. Tarnopolsky M. A., MacDougall J. D., Atkinson S. A. Influence of protein intake and training status on nitrogen balance and lean body mass. J Appl Physiol (1985) 1988 Jan;64(1):187–193. doi: 10.1152/jappl.1988.64.1.187. [DOI] [PubMed] [Google Scholar]
  37. Wagenmakers A. J., Brookes J. H., Coakley J. H., Reilly T., Edwards R. H. Exercise-induced activation of the branched-chain 2-oxo acid dehydrogenase in human muscle. Eur J Appl Physiol Occup Physiol. 1989;59(3):159–167. doi: 10.1007/BF02386181. [DOI] [PubMed] [Google Scholar]
  38. van der Hulst R. R., van Kreel B. K., von Meyenfeldt M. F., Brummer R. J., Arends J. W., Deutz N. E., Soeters P. B. Glutamine and the preservation of gut integrity. Lancet. 1993 May 29;341(8857):1363–1365. doi: 10.1016/0140-6736(93)90939-e. [DOI] [PubMed] [Google Scholar]

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