The Effects of a High Carbohydrate Diet on Cortisol and Salivary Immunoglobulin A (s-IgA) During a Period of Increase Exercise Workload Amongst Olympic and Ironman Triathletes

Abstract

The present study observed the effects of a 6-day high carbohydrate (H-CHO) diet on salivary cortisol and IgA during a period of increased exercise workload. Thirty-two competitively trained male triathletes were randomly allocated into a self-selected (SS), or an H-CHO (12 g CHO kgbm^-1 · day^-1) dietary group. In addition to their training regimes, all subjects performed a 1-hour running exercise bout at 70 % V·O_2max · d^-1, for six days. Saliva samples were taken pre, immediately post, and morning post-exercise bout on days 1, 4, and 6. The concentrations of s-IgA and cortisol were determined by ELISA assays. There was a significant (p < 0.001) interaction between Group × Time for cortisol, with a marked increase in concentrations occurring in the SS dietary group pre to post exercise, and pre to morning post-exercise (p < 0.01). Conversely, a significant (p = 0.009) Group × Time interaction reflected higher post exercise s-IgA concentrations (p < 0.005) than pre exercise in the H-CHO diet group. Blood glucose concentration decreased pre to post exercise in the SS diet group (p < 0.01), whilst remaining stable in the H-CHO group. It is concluded that the consumption of a high CHO diet throughout a 6-day period of overtraining had a favourable effect on markers of immune activity and thereby reduced the susceptibility of these endurance athletes to upper respiratory tract infection URTI.

Stress hormone - URTI - training - immunosuppressive - endurance - overtraining

References

• 1 Bacurau R FP, Bassit R A, Sawada L, Navarro F, Martins E, Rosa L. Carbohydrate supplementation during intense exercise and the immune response of cyclists.  Clin Nutr. 2002;  21 423-429
• 2 Bishop N C, Blannin A K, Rand L, Gleeson M. Effects of carbohydrate and fluid intake on the blood leukocyte response to prolonged cycling.  J Sport Sci. 1999;  17 26-27
• 3 Bishop N C, Blannin A K, Walsh N P, Robson P J, Gleeson M. Nutritional aspects of immunosuppression in athletes.  Sports Med. 1999;  28 151-176
• 4 Bishop N C, Blannin A K, Armstrong E, Rickman M, Gleeson M. Carbohydrate and fluid intake affect the saliva flow rate and IgA response to cycling.  Med Sci Sport Exer. 2000;  32 2046-2051
• 5 Brenner I KM, Severs Y D, Rhind S G, Shephard R J, Shek P N. Immune function and incidence of infection during basic infantry training.  Milit Med. 2000;  165 878-883
• 6 Corral P, Mahon A D, Duncan G E, Howe C A, Craig B W. The effect of exercise on serum and salivary cortisol in male children.  Med Sci Sport Exerc. 1994;  26 1297-1301
• 7 Costill D L, Flynn M G, Kirwan J P, Houmard J A, Mitchell J B, Thomas R, Park S H. Effects of repeated days of intensified training on muscle glycogen and swimming performance.  Med Sci Sport Exerc. 1988;  20 249-254
• 8 Costill D L. Carbohydrate for exercise: dietary demands for optimal performance.  Int J Sport Med. 1988;  9 1-18
• 9 Espersen G T, Elbaeck A, Schmidt-Olsen S, Ejlersen E, Varming K, Grunnet N. Short-term changes in the immune system of elite swimmers under competitive conditions. Different immunomodulation induced by various types of sports.  Scan J Med Sci Sport. 1996;  6 156-163
• 10 Fitzgerald L. Overtraining increases the susceptibility of infection.  Int J Sport Med. 1991;  12 5-8
• 11 Foster C. Monitoring training in athletes with reference to overtraining syndrome.  Med Sci Sport Exerc. 1998;  30 1164-1168
• 12 Frayn (ed) K N. Metabolic Regulation: A Human Perspective. London; Portland Press 1999 103-110 174-195
• 13 Gleeson M, Blannin A K, Walsh N P, Bishop N C, Clark A M. Effects of low- and high-carbohydrate diets on the plasma glutamine and circulating leukocyte responses to exercise.  Int J Sport Nutr. 1998;  8 49-59
• 14 Gleeson M, Hall S T, McDonald W A, Flanagan A J, Clancy R L. Salivary IgA subclasses and infection risk in elite swimmers.  Immunol Cell Biol. 1999;  77 351-355
• 15 Gleeson M, Nieman D C, Pedersen B K. Exercise, nutrition and immune function.  J Sport Sci. 2004;  22 115-125
• 16 Hale T, Armstrong N, Hardman A, Jakeman P, Sharp C, Winter E. Position Statement on the Physiological Assessment of the Elite Competitor. Leeds; British Association of Sports Science 1996
• 17 Harris B, Watkins S, Cook N, Walker R F, Read G F, Riad-Fahmy D. Comparisons of plasma and salivary cortisol determinations for the diagnostic efficacy of the dexamethasone suppression test.  Bio Psychiat. 1990;  27 897-904
• 18 Henson D A, Nieman D C, Blodgett A D, Butterworth D E, Utter A, Davis J M, Sonnenfeld G, Morton D S, Fagoaga O R, Nehlsen-Cannarella S L. Influence of exercise mode and carbohydrate on the immune response to prolonged exercise.  Int J Sport Nutr. 1999;  9 213-228
• 19 Ivy J L. Muscle glycogen synthesis before and after exercise.  Sport Med. 1991;  11 6-19
• 20 Kingsbury K J, Hjelm M, Kay L. Contrasting plasma free amino acid patterns in elite athletes: association with fatigue and infection.  Br J Sport Med. 1998;  32 25-33
• 21 Kohut M L, Boehm G W, Moynihan J A. Prolonged exercise suppresses antigen-specific cytokine response to upper respiratory tract infection.  J Appl Physiol. 2001;  90 678-684
• 22 MacKinnon L T. Overtraining effects on immunity and performance in athletes.  Immunol Cell Biol. 2000;  78 502-509
• 23 Nehlsen-Cannarella S L, Fagoaga O R, Nieman D C, Henson D A, Butterworth D E, Schmitt R L, Bailey E M, Warren B J, Utter A, Davis J M. Carbohydrate and the cytokine response to 2.5 h of running.  J Appl Physiol. 1997;  82 1662-1667
• 24 Nieman D C, Fagoaga O R, Butterworth D E, Warren B J, Utter A, Davis J M, Henson D A, Nehlsen-Cannarella S L. Carbohydrate supplementation affects blood granulocyte and monocyte trafficking, but not function after 2.5 h running.  Am J Clin Nutr. 1997;  66 153-159
• 25 Nieman D C, Henson D A, Garner E B, Butterworth D E, Warren B J, Utter A, Davis J M, Nehlsen-Cannarella S L, Fagoaga O R. Carbohydrate affects natural killer cell redistribution but not function after running.  Med Sci Sport Exerc. 1997;  20 1318-1324
• 26 Nieman D C. Influence of carbohydrate on the immune response to intensive, prolonged exercise.  Exerc Immunol Rev. 1998;  4 64-76
• 27 Pyne D B, Gleeson M, McDonald W A, Clancy R L, Perry Jr C, Fricker P A. Training strategies to maintain immunocompetence in athletes.  Int J Sports Med. 2000;  21 51-60
• 28 Robson P J, Blannin A K, Walsh N P, Castell L M, Gleeson M. Effects of exercise intensity, duration, and recovery on in vitro neutrophil function in male athletes.  Int J Sports Med. 1999;  20 1-8
• 29 Ronsen O, Haug E, Pedersen B K, Bahr R. Increased neurendocrine response to a repeated bout of endurance exercise.  Med Sci Sport Exerc. 2001;  33 568-575
• 30 Tharp G D, Barnes M W. Reduction of saliva immunoglobulin levels by swim training.  Eur J Appl Physiol. 1990;  60 61-64
• 31 Tomasi T B, Trudeau F B, Czerwinski D, Erredge S. Immune parameters in athletes before and after strenuous exercise.  J Clin Immunol. 1982;  2 173-178
• 32 Tsintzas O K, Williams C, Wilson W, Burrin J. Influence of carbohydrate supplementation early in exercise on endurance running capacity.  Med Sci Sport Exerc. 1996;  28 1373-1379
• 33 Winter E M, Eston R G, Lamb K L. Statistical analyses in the physiology of exercise and kinanthropometry.  J Sports Sci. 2001;  19 761-776