Advertisement

Sports Medicine

, Volume 35, Issue 2, pp 163–181 | Cite as

Nutritional Considerations in Triathlon

  • Asker E. Jeukendrup
  • Roy L. P. G. Jentjens
  • Luke Moseley
Review Article

Abstract

Triathlon combines three disciplines (swimming, cycling and running) and competitions last between 1 hour 50 minutes (Olympic distance) and 14 hours (Ironman distance). Independent of the distance, dehydration and carbohydrate (CHO) depletion are the most likely causes of fatigue in triathlon, whereas gastrointestinal (GI) problems, hyperthermia and hyponatraemia are potentially health threatening, especially in longer events. Although glycogen supercompensation may be beneficial for triathlon performance (even Olympic distance), this does not necessarily have to be achieved by the traditional supercompensation protocol. More recently, studies have revealed ways to increase muscle glycogen concentrations to very high levels with minimal modifications in diet and training.

During competition, cycling provides the best opportunity to ingest fluids. The optimum CHO concentration seems to be in the range of 5–8% and triathletes should aim to achieve a CHO intake of 60–70 g/hour. Triathletes should attempt to limit body mass losses to 1% of body mass. In all cases, a drink should contain sodium (30–50 mmol/L) for optimal absorption and prevention of hyponatraemia.

Post-exercise rehydration is best achieved by consuming beverages that have a high sodium content (>60 mmol/L) in a volume equivalent to 150% of body mass loss. GI problems occur frequently, especially in long-distance triathlon. Problems seem related to the intake of highly concentrated carbohydrate solutions, or hyperosmotic drinks, and the intake of fibre, fat and protein. Endotoxaemia has been suggested as an explanation for some of the GI problems, but this has not been confirmed by recent research. Although mild endotoxaemia may occur after an Ironman-distance triathlon, this does not seem to be related to the incidence of GI problems. Hyponatraemia has occasionally been reported, especially among slow competitors in triathlons and probably arises due to loss of sodium in sweat coupled with very high intakes (8–10L) of water or other low-sodium drinks.

Keywords

Muscle Glycogen Muscle Glycogen Synthesis Muscle Glycogen Concentration Glycogen Synthesis Rate Ironman Distance 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgements

The research of the authors is funded by Glaxo-SmithKline, Consumer Healthcare.

References

  1. 1.
    Coyle EF. Substrate utilization during exercise in active people. Am J Clin Nutr 1995; 61: 968–79Google Scholar
  2. 2.
    Holloszy JO, Kohrt WM. Regulation of carbohydrate and fat metabolism during and after exercise. Ann Rev Nutr 1996; 16: 121–38Google Scholar
  3. 3.
    Ivy JL. Role of carbohydrate in physical activity. Clin Sports Med 1999; 18: 469–84PubMedGoogle Scholar
  4. 4.
    Romijn JA, Coyle EF, Sidossis LS, et al. Regulation of endogenous fat and carbohydrate metabolism in relation to exercise intensity. Am J Physiol 1993; 265: E380–91Google Scholar
  5. 5.
    Bergström J, Hermansen L, Hultman E, et al. Diet, muscle glycogen and physical performance. Acta Physiol Scand 1967; 71: 140–50PubMedGoogle Scholar
  6. 6.
    Hultman E. Physiological role of muscle glycogen in man, with special reference to exercise. Circ Res 1967; 10: I99-I114Google Scholar
  7. 7.
    Coyle EF, Coggan AR, Hemmert MK, et al. Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate. J Appl Physiol 1986; 61: 165–72PubMedGoogle Scholar
  8. 8.
    Noakes TD. Physiological models to understand exercise fatigue and the adaptations that predict or enhance athletic performance. Scand J Med Sci Sports 2000; 10: 123–45PubMedGoogle Scholar
  9. 9.
    Coyle EF. Fluid and fuel intake during exercise. J Sports Sci 2004; 22: 39–55PubMedGoogle Scholar
  10. 10.
    Sawka MN, Pandolf KB. Effects of body water loss in physiological function and exercise performance. In: Lamb DR, Gisolfi CV, editors. Perspectives in exercise science and sports medicine: fluid homeostasis during exercise. Indianapolis (IN): Benchmark Press, 1990: 1–38Google Scholar
  11. 11.
    Bentley DJ, Millet GP, Vleck VE, et al. Specific aspects of contemporary triathlon: implications for physiological analysis and performance. Sports Med 2002; 32: 345–59PubMedGoogle Scholar
  12. 12.
    Moseley L, Jeukendrup AE. The reliability of cycling efficiency. Med Sci Sports Exerc 2001; 33: 621–7PubMedGoogle Scholar
  13. 13.
    Sawka MN. Physiological consequences of hypohydration: exercise performance and thermoregulation. Med Sci Sports Exerc 1992; 24: 657–70PubMedGoogle Scholar
  14. 14.
    Febbraio MA, Snow RJ, Stathis CG, et al. Effect of heat stress on muscle energy metabolism during exercise. J App Physiol 1994; 77: 2827–31Google Scholar
  15. 15.
    Fink WJ, Costill DL, Van Handel PJ. Leg muscle metabolism during exercise in the heat and cold. Eur J App Physiol 1975; 34: 183–90Google Scholar
  16. 16.
    Jentjens RL, Wagenmakers AJ, Jeukendrup AE. Heat stress increases muscle glycogen use but reduces the oxidation of ingested carbohydrates during exercise. J Appl Physiol 2002; 92: 1562–72PubMedGoogle Scholar
  17. 17.
    Pitsiladis YP, Maughan RJ. The effects of exercise and diet manipulation on the capacity to perform prolonged exercise in the heat and in the cold in trained humans. J Physiol 1999; 517: 919–30PubMedGoogle Scholar
  18. 18.
    Gonzales-Alonso J, Teller C, Andersen SL, et al. Influence of body temperature on the development of fatigue during prolonged exercise in the heat. J Appl Physiol 1999; 86: 1032–9Google Scholar
  19. 19.
    Nielsen B, Hales JRS, Strange NJ, et al. Human circulatory and thermoregulatory adaptations with heat acclimation and exercise in a hot, dry enviroment. J Physiol 1993; 460: 467–85PubMedGoogle Scholar
  20. 20.
    Cheuvront SN, Carter III R, Sawka MN. Fluid balance and endurance exercise performance. Curr Sports Med Rep 2003; 2: 202–8PubMedGoogle Scholar
  21. 21.
    Walsh RM, Noakes TD, Hawley JA, et al. Impaired high-intensity cycling performance time at low levels of dehydration. Int J Sports Med 1994; 15: 392–8PubMedGoogle Scholar
  22. 22.
    Armstrong LE, Costill DL, Fink WJ. Influence of diruetic-induced dehydration on competitive running performance. Med Sci Sports Exerc 1985; 17: 456–61PubMedGoogle Scholar
  23. 23.
    Rehrer NJ, Beckers EJ, Brouns F, et al. Effects of dehydration on gastric emptying and gastrointestinal distress while running. Med Sci Sports Exerc 1990; 22: 790–5PubMedGoogle Scholar
  24. 24.
    Rogers G, Goodman C, Rosen C. Water budget during ultra-endurance exercise. Med Sci Sports Exerc 1997; 29: 1477–81PubMedGoogle Scholar
  25. 25.
    Hawley JA, Schabort EJ, Noakes TD, et al. Carbohydrate loading and exercise performance: an update. Sports Med 1997; 24 (2): 73–81PubMedGoogle Scholar
  26. 26.
    Sherman WM, Costill DL, Fink WJ, et al. Effect of exercise-diet manipulation on muscle glycogen and its subsequent utilisation during performance. Int J Sports Med 1981; 2: 114–8PubMedGoogle Scholar
  27. 27.
    Coyle EF, Jeukendrup AE, Oseto MC, et al. Low-fat diet alters intramuscular substrates and reduces lipolysis and fat oxidation during exercise. Am J Physiol Endocrinol Metab 2001; 280: E391–8Google Scholar
  28. 28.
    Fairchild TJ, Fletcher S, Steele P, et al. Rapid carbohydrate loading after a short bout of near maximal-intensity exercise. Med Sci Sports Exerc 2002; 34: 980–6PubMedGoogle Scholar
  29. 29.
    Bussau VA, Fairchild TJ, Rao A, et al. Carbohydrate loading in human muscle: an improved 1 day protocol. Eur J Appl Physiol 2002; 87: 290–5PubMedGoogle Scholar
  30. 30.
    Goforth HW, Arnall DA, Bennett BL, et al. Persistence of supercompensated muscle glycogen in trained subjects after carbohydrate loading. J Appl Physiol 1997; 82: 342–7PubMedGoogle Scholar
  31. 31.
    Coyle EF, Coggan AR, Hemmert MK, et al. Substrate usage during prolonged exercise following a preexercise meal. J Appl Physiol 1985; 59: 429–33PubMedGoogle Scholar
  32. 32.
    Burke LM, Hawley JM. Carbohydrate and exercise. Curr Opin Clin Nutr Metab Care 1999; 2: 515–20PubMedGoogle Scholar
  33. 33.
    Hargreaves M. Metabolic responses to carbohydrate ingestion: effects on exercise performance. In: Lamb DR, Murray R, editors. Perspectives in exercise science and sports medicine: the metabolic basis of performance in exercise and sport. Carmel: Cooper Publishing Group LLC, 1999, 93–124Google Scholar
  34. 34.
    Hargreaves M, Hawley JA, Jeukendrup AE. Pre-exercsie carbohydrate and fat ingestion: effects on metabolism and performance. J Sports Sci 2004; 22: 31–8PubMedGoogle Scholar
  35. 35.
    Sherman WM, Brodowicz G, Wright DA, et al. Dernbach. Effects of 4h preexercise carbohydrate feedings on cycling performance. Med Sci Sports Exerc 1989; 21: 598–604PubMedGoogle Scholar
  36. 36.
    Wright DA, Sherman WM, Dernbach AR. Carbohydrate feedings before, during, or in combination improve cycling endurance performance. J Appl Physiol 1991; 71: 1082–8PubMedGoogle Scholar
  37. 37.
    Foster C, Costill DL, Fink WJ. Effects of preexercise feedings on endurance performance. Med Sci Sports 1979; 11: 1–5PubMedGoogle Scholar
  38. 38.
    Keller K, Schwarzkopf R. Preexercise snacks may decrease exercise performance. Phys Sportsmed 1984; 12: 89–91Google Scholar
  39. 39.
    Costill DL, Coyle E, Dalsky G, et al. Effects of elevated plasma FFA and insulin on muscle glycogen usage during exercise. J App Physiol 1977; 43: 695–9Google Scholar
  40. 40.
    Koivisto VA, Karonen SL, Nikkila EA. Carbohydrate ingestion before exercise: comparison of glucose, fructose, and sweet placebo. J Appl Physiol 1981; 51: 783–7PubMedGoogle Scholar
  41. 41.
    Marmy-Conus N, Fabris S, Proietto J, et al. Preexercise glucose ingestion and glucose kinetics during exercise. J Appl Physiol 1996; 81: 853–7PubMedGoogle Scholar
  42. 42.
    Chryssanthopoulos C, Hennessy LC, Williams C. The influence of pre-exercise glucose ingestion on endurance running capacity. Br J Sports Med 1994; 28: 105–9PubMedGoogle Scholar
  43. 43.
    Febbraio M, Stewart K. CHO feedings before prolonged exercise: effect of glycemic index on muscle glycogenolysis and exercise performance. J Appl Physiol 1996; 81: 1115–20PubMedGoogle Scholar
  44. 44.
    Febbraio MA, Keenan J, Angus DJ, et al. Preexercise carbohydrate ingestion, glucose kinetics, and muscle glycogen use: effect of the glycemic index. J Appl Physiol 2000; 89: 1845–51PubMedGoogle Scholar
  45. 45.
    Hargreaves M, Costill DL, Fink WJ, et al. Effect of pre-exercise carbohydrate feedings on endurance cycling performance. Med Sci Sports Exerc 1987; 19: 33–6PubMedGoogle Scholar
  46. 46.
    Sparks MJ, Selig SS, Febbraio MA. Pre-exercise carbohydrate ingestion: effect of the glycemic index on endurance exercise performance. Med Sci Sports Exerc 1998; 30: 844–9PubMedGoogle Scholar
  47. 47.
    Gleeson M, Maughan RJ, Greenhaff PL. Comparison of the effects of pre-exercise feeding of glucose, glycerol and placebo on endurance and fuel homeostasis in man. Eur J Appl Physiol 1986; 55: 645–53Google Scholar
  48. 48.
    Kirwan JP, O’Gorman D, Evans WJ. A moderate glycemic meal before endurance exercise can enhance performance. J Appl Physiol 1998; 84: 53–9PubMedGoogle Scholar
  49. 49.
    Sherman WM, Peden MC, Wright DA. Carbohydrate feedings 1h before exercise improves cycling performance. Am J Clin Nutr 1991; 54: 866–70PubMedGoogle Scholar
  50. 50.
    Speedy D, Kelly M, O’Brien M. The effect of pre-exercise feeding on endurance exercise performance. NZ J Sports Med 1998; 26: 34–7Google Scholar
  51. 51.
    Thomas DE, Brotherhood JR, Brand JC. Carbohydrate feeding before exercise: effect of glycemic index. Int J Sports Med 1991; 12: 180–6PubMedGoogle Scholar
  52. 52.
    Jentjens RL, Cale C, Gutch C, et al. Effects of pre-exercise ingestion of differing amounts of carbohydrate on subsequent metabolism and cycling performance. Eur J Appl Physiol 2003; 88: 444–52PubMedGoogle Scholar
  53. 53.
    Jentjens RL, Jeukendrup AE. Effects of pre-exercise ingestion of trehalose, galactose and glucose on subsequent metabolism and cycling performance. Eur J Appl Physiol 2003; 88: 459–65PubMedGoogle Scholar
  54. 54.
    Mitchell JB, Braun WA, Pizza FX, et al. Pre-exericse carbohydrate and fluid ingestion: influence of glycemic response on 10-km treadmill running performance in the heat. J Sports Med Phys Fitness 2000; 40: 41–50PubMedGoogle Scholar
  55. 55.
    Moseley L, Lancaster GI, Jeukendrup AE. Effects of timing of pre-exercise ingestion of carbohydrate on subsequent metabolism and cycling performance. Eur J Appl Physiol 2003; 88: 453–8PubMedGoogle Scholar
  56. 56.
    van Zant RS, Lemon PWR. Preexercise sugar feeding does not alter prolonged exercise muscle glycogen or protein catabolism. Can J Appl Physiol 1997; 22: 268–79PubMedGoogle Scholar
  57. 57.
    Jentjens RL, Jeukendrup AE. Prevalence of hypoglycemia following pre-exercise carbohydrate ingestion is not accompanied by higher insulin sensitivity. Int J Sport Nutr Exerc Metab 2002; 12: 398–413PubMedGoogle Scholar
  58. 58.
    Kuipers H, Fransen EJ, Keizer HA. Pre-exercise ingestion of carbohydrate and transient hypoglycemia during exercise. Int J Sports Med 1999; 20: 227–31PubMedGoogle Scholar
  59. 59.
    Wee SL, Williams C, Gray S, et al. Influence of high and low glycemic index meals on endurance running capacity. Med Sci Sports Exerc 1999; 31: 393–9PubMedGoogle Scholar
  60. 60.
    Convertino VA, Armstrong LE, Coyle EF, et al. American College of Sports Medicine position stand: exercise and fluid replacement. Med Sci Sports Exerc 1996; 28: i-viiPubMedGoogle Scholar
  61. 61.
    Latzka WA, Sawka MN. Hyperhydration and glycerol: thermoregulatory effects during exercise in hot climates. Can J Appl Physiol 2000; 25: 536–45PubMedGoogle Scholar
  62. 62.
    Robergs RA, Griffin SE. Glycerol: biochemistry, pharmacokinetics and clinical and practical applications. Sports Med 1998; 26 (3): 145–67PubMedGoogle Scholar
  63. 63.
    Coutts A, Reaburn P, Mummery K, et al. The effect of glycerol hyperhydration on olympic distance triathlon performance in high ambient temperatures. Int J Sport Nutr Exerc Metab 2002; 12: 105–19PubMedGoogle Scholar
  64. 64.
    Marino FE, Kay D, Cannon J. Glycerol hyperhydration fails to improve endurance performance and thermoregulation in humans in a warm humid environment. Pflugers Arch 2003; 446: 455–62PubMedGoogle Scholar
  65. 65.
    Rehrer NJ. Fluid and electrolyte balance in ultra-endurance sport. Sports Med 2001; 31 (10): 701–15PubMedGoogle Scholar
  66. 66.
    Coggan AR, Coyle EF. Reversal of fatigue during prolonged exercise by carbohydrate infusion or ingestion. J Appl Physiol 1987; 63: 2388–95PubMedGoogle Scholar
  67. 67.
    Anantaraman R, Carmines AA, Gaesser GA, et al. Effects of carbohydrate supplementation on performance during 1h of high intensity exercise. Int J Sports Med 1995; 16: 461–5PubMedGoogle Scholar
  68. 68.
    Below PR, Mora-Rodríguez R, Gonzáles Alonso J, et al. Fluid and carbohydrate ingestion independently improve performance during 1h of intense exercise. Med Sci Sports Exerc 1995; 27: 200–10PubMedGoogle Scholar
  69. 69.
    Jeukendrup A, Brouns F, Wagenmakers AJ, et al. Carbohydrate-electrolyte feedings improve 1h time trial cycling performance. Int J Sports Med 1997; 18: 125–9PubMedGoogle Scholar
  70. 70.
    Kimber NE, Ross JJ, Mason SL, et al. Energy balance during an ironman triathlon in male and female triathletes. Int J Sport Nutr Exerc Metab 2002; 12: 47–62PubMedGoogle Scholar
  71. 71.
    Jeukendrup AE, Raben A, Gijsen A, et al. Glucose kinetics during prolonged exercise in highly trained human subjects: effect of glucose ingestion. J Physiol 1999; 515: 579–589, 1999Google Scholar
  72. 72.
    Jeukendrup AE, Wagenmakers AJ, Stegen JH, et al. Carbohydrate ingestion can completely suppress endogenous glucose production during exercise. Am J Physiol 1999; 276: E672–83Google Scholar
  73. 73.
    Tsintzas OK, Williams C, Boobis L, et al. Carbohydrate ingestion and glycogen utilisation in different muscle fibre types in man. J Physiol 1995; 489: 243–50PubMedGoogle Scholar
  74. 74.
    Tsintzas K, Williams C. Human muscle glycogen metabolism during exercise: effect of carbohydrate supplementation. Sports Med 1998; 25 (1): 7–23PubMedGoogle Scholar
  75. 75.
    Shi X, Summers RW, Schedl HP, et al. Effects of carbohydrate type and concentration and solution osmolality on water absorption. Med Sci Sports Exerc 1995; 27: 1607–15PubMedGoogle Scholar
  76. 76.
    Adopo E, Peronnet F, Massicotte D, et al. Respective oxidation of exogenous glucose and fructose given in the same drink during exercise. J Appl Physiol 1994; 76: 1014–9PubMedGoogle Scholar
  77. 77.
    Jentjens RL, Moseley L, Waring RH, et al. Oxidation of combined ingestion of glucose and fructose during exercise. J Appl Physiol 2004; 96: 1277–84PubMedGoogle Scholar
  78. 78.
    Jentjens RL, Venables MC, Jeukendrup AE. Oxidation of exogenous glucose, sucrose, and maltose during prolonged cycling exercise. J Appl Physiol 2004; 96: 1285–91PubMedGoogle Scholar
  79. 79.
    Jeukendrup AE, Jentjens R. Oxidation of carbohydrate feedings during prolonged exercise: current thoughts, guidelines and directions for future research. Sports Med 2000; 29 (6): 407–24PubMedGoogle Scholar
  80. 80.
    Guezennec CY, Vallier JM, Bigard AX, et al. Increase in energy cost of running at the end of a triathlon. Eur J App Physiol 1996; 73: 440–5Google Scholar
  81. 81.
    Backx KK, van Someren A, Palmer GS. One hour cycling performance is not affected by ingested fluid volume. Int J Sport Nutr Exerc Metab 2003; 13: 333–42PubMedGoogle Scholar
  82. 82.
    Robinson TA, Hawley JA, Palmer GS, et al. Water ingestion does not improve 1h cycling performance in moderate ambient temperatures. Eur J Appl Physiol 1995; 71: 153–60Google Scholar
  83. 83.
    Costill DL, Saltin B. Factors limiting gastric emptying during rest and exercise. J App Physiol 1974; 37: 679–83Google Scholar
  84. 84.
    Leiper JB, Broad NP, Maughan RJ. Effect of intermittent high-intensity exercise on gastric emptying in man. Med Sci Sports Exerc 2001; 33: 1270–8PubMedGoogle Scholar
  85. 85.
    Rehrer NJ, Brouns F, Beckers EJ, et al. The influence of beverage composition and gastrointestinal function on fluid and nutrient availability during exercise: a review. Scand J Med Sci Sports 1994; 4: 159–72Google Scholar
  86. 86.
    Dennis SC, Noakes TD, Hawley JA. Nutritional strategies to minimize fatigue during prolonged exercise: fluid, electrolyte and energy replacement. J Sport Sci 1997; 15: 305–13Google Scholar
  87. 87.
    Hunt JN, Spurrell WR. The pattern of emptying of the human stomach. J Physiol 1958; 113: 157–68Google Scholar
  88. 88.
    Hunt JN, Smith JL, Jiang CL. Effect of meal volume and energy density on the gastric emptying of carbohydrates. Gastroenterology 1985; 89: 1326–30PubMedGoogle Scholar
  89. 89.
    Mitchell JB, Voss KW. The influence of volume on gastric emptying and fluid balance during prolonged exercise. Med Sci Sports Exerc 1991; 23: 314–9PubMedGoogle Scholar
  90. 90.
    Noakes TD, Rehrer NJ, Maughan RJ. The importance of volume in regulating gastric emptying. Med Sci Sports Exerc 1991; 23: 307–13PubMedGoogle Scholar
  91. 91.
    Rehrer NJ, Brouns F, Beckers EJ, et al. Gastric emptying with repeated drinking during running and bicycling. Int J Sports Med 1990; 11: 238–43PubMedGoogle Scholar
  92. 92.
    Parsons DS, Wingate DL. The effect of osmotic gradients on fluid transfer across rat intestines in vitro. Biochem Biophys Acta 1961; 46: 107–83Google Scholar
  93. 93.
    Olsen WA, Inglefinger FJ. The role of sodium in intestinal glucose absorption in man. J Clin Invest 1968; 47: 1133–42PubMedGoogle Scholar
  94. 94.
    Loo DD, Zeuthen T, Chandy G, et al. Cotransport of water by the Na+/glucose cotransporter. Proc Natl Acad Sci U S A 1996; 93: 13367–70PubMedGoogle Scholar
  95. 95.
    Gisolfi C, Summers R, Schedl H, et al. Intestinal water absorption from select carbohydrate solutions in humans. Med Sci Sports Exerc 1992; 24: S939Google Scholar
  96. 96.
    Gisolfi CV, Spranger KJ, Summers RW, et al. Effects of cycle exercise on intestinal absorption in humans. J App Physiol 1991; 71: 2518–27Google Scholar
  97. 97.
    Gisolfi CV, Summers RD, Schedl HP, et al. Effect of sodium concentration in a carbohydrate-electrolyte solution on intestinal absorption. Med Sci Sports Exerc 1995; 27: 1414–20PubMedGoogle Scholar
  98. 98.
    Hargreaves M, Costill DL, Burke L, et al. Influence of sodium on glucose bioavalability during exercise. Med Sci Sports Exerc 1994; 26: 365–8PubMedGoogle Scholar
  99. 99.
    Maughan RJ. The sports drink as a functional food: formulations for successful performance. Proc Nutr Soc 1998; 57: 15–23PubMedGoogle Scholar
  100. 100.
    Rehrer NJ, van Kemenade M, Meester W, et al. Gastrointestinal complaints in relation to dietary intake in triathletes. Int J Sport Nutr 1992; 2: 48–59PubMedGoogle Scholar
  101. 101.
    Ryan AJ, Lambert GP, Shi X, et al. Effect of hypohydration on gastric emptying and intestinal absorption during exercise. J Appl Physiol 1998; 84: 1581–8PubMedGoogle Scholar
  102. 102.
    Brouns F, Senden J, Beckers EJ, et al. Osmolarity does not affect the gastric emptying rate of oral rehydration solutions. JPEN J Parenter Enteral Nutr 1995; 19: 403–6PubMedGoogle Scholar
  103. 103.
    Murray R, Eddy DE, Bartoli WP, et al. Gastric emptying of water and isocaloric carbohydrate solutions consumed at rest. Med Sci Sports Exerc 1994; 26: 725–32PubMedGoogle Scholar
  104. 104.
    Passe DH, Horn M, Murray R. Impact of beverage acceptability on fluid intake during exercise. Appetite 2000; 35: 219–29PubMedGoogle Scholar
  105. 105.
    Applegate E. Nutritional concerns of the ultraendurance triathlete. Med Sci Sports Exerc 1989; 21: S205–8Google Scholar
  106. 106.
    Coyle EF, Montain SJ. Carbohydrate and fluid ingestion during exercise: are there trade-offs? Med Sci Sports Exerc 1992; 24: 671–8PubMedGoogle Scholar
  107. 107.
    Laursen PB, Rhodes EC. Factors affecting performance in an ultraendurance triathlon. Sports Med 2001; 31 (3): 195–209PubMedGoogle Scholar
  108. 108.
    Millard-Stafford M, Sparling PB, Rosskopf LB, et al. Carbohydrate-electrolyte replacement during a simulated triathlon in the heat. Med Sci Sports Exerc 1990; 22: 621–8PubMedGoogle Scholar
  109. 109.
    Keizer H, Kuipers H, van Kranenburg G. Influence of liquid and solid meals on muscle glycogen resynthesis, plasma fuel hormone response, and maximal physical working capacity. Int J Sports Med 1987; 8: 99–104PubMedGoogle Scholar
  110. 110.
    Kochan RG, Lamb DR, Lutz SA, et al. Glycogen synthase activation in human skeletal muscle: effects of diet and exercise. Am J Physiol 1979; 5: E660–6Google Scholar
  111. 111.
    Starling RD, Trappe TA, Parcell AC, et al. Effects of diet on muscle triglyceride and endurance performance. J Appl Physiol 1997; 82: 1185–9PubMedGoogle Scholar
  112. 112.
    Nicholas CW, Green PA, Hawkins RD, et al. Carbohydrate intake and recovery of intermittent running capacity. Int J Sport Nutr 1997; 7: 251–60PubMedGoogle Scholar
  113. 113.
    Fallowfield JL, Williams C. Carbohydrate intake and recovery from prolonged exercise. Int J Sports Nutr 1993; 3: 150–64Google Scholar
  114. 114.
    Asp S, Rohde T, Richter EA. Impaired muscle glycogen resynthesis after a marathon is not caused by decreased muscle GLUT4 content. J Appl Physiol 1997; 83: 1482–5PubMedGoogle Scholar
  115. 115.
    Costill DL, Pascoe DD, Fink WJ, et al. Impaired muscle glycogen resynthesis after eccentric exercise. J Appl Physiol 1990; 69: 46–50PubMedGoogle Scholar
  116. 116.
    Widrick JJ, Costill DL, Fink WJ, et al. Carbohydrate feedings and exercise performance: effect of initial glycogen concentration. J Appl Physiol 1993; 74: 2998–3005PubMedGoogle Scholar
  117. 117.
    Burke L, Collier GR, Beasley SB, et al. Effect of coingestion of fat and protein with carbohydrate feedings on muscle glycogen storage. J Appl Physiol 1995; 78: 2187–92PubMedGoogle Scholar
  118. 118.
    Burke L, Collier GR, Davis PG, et al. Muscle glycogen storage after prolonged exercise: effect of the frequency of carbohydrate feedings. Am J Clin Nutr 1996; 64: 115–9PubMedGoogle Scholar
  119. 119.
    Burke LM, Collier GR, Hargreaves M. Muscle glycogen storage after prolonged exercise: effect of glycemic index of carbohydrate feedings. J Appl Physiol 1993; 75: 1019–23PubMedGoogle Scholar
  120. 120.
    Jentjens R, Jeukendrup A. Determinants of post-exercise glycogen synthesis during short-term recovery. Sports Med 2003; 33 (2): 117–44PubMedGoogle Scholar
  121. 121.
    Jentjens RL, van Loon LJ, Mann CH, et al. Addition of protein and amino acids to carbohydrates does not enhance postexercise muscle glycogen synthesis. J Appl Physiol 2001; 91: 839–46PubMedGoogle Scholar
  122. 122.
    van Hall G, Shirreffs SM, Calbet JA. Muscle glycogen resynthesis during recovery from cycle exercise: no effect of additional protein ingestion. J Appl Physiol 2000; 88: 1631–6PubMedGoogle Scholar
  123. 123.
    van Loon LJ, Saris WH, Kruijshoop M, et al. Maximizing postexercise muscle glycogen synthesis: carbohydrate supplementation and the application of amino acid or protein hydrolysate mixtures. Am J Clin Nutr 2000; 72: 106–11PubMedGoogle Scholar
  124. 124.
    Ivy JL. Muscle glycogen synthesis before and after exercise. Sports Med 1991; 11 (1): 6–19PubMedGoogle Scholar
  125. 125.
    Ivy JL, Lee MC, Brozinick JT, et al. Muscle glycogen storage after different amounts of carbohydrate ingestion. J Appl Physiol 1988; 65: 2018–23PubMedGoogle Scholar
  126. 126.
    Blom PCS, Høstmark AT, Vaage O, et al. Effect of different post-exercise sugar diets on the rate of muscle glycogen resynthesis. Med Sci Sports Exerc 1987; 19: 491–6PubMedGoogle Scholar
  127. 127.
    Fujisawa T, Mulligan K, Wada L, et al. The effect of exercise on fructose absorption. Am J Clin Nutr 1993; 58: 75–9PubMedGoogle Scholar
  128. 128.
    Henry AW, Crapo PA, Thorburn AW. Current issues in fructose metabolism. Ann Rev Nutr 1991; 11: 21–39Google Scholar
  129. 129.
    Chen M, Whistler RL. Metabolism of D-fructose. Adv Carbohydr Chem Biochem 1977; 34: 265–343PubMedGoogle Scholar
  130. 130.
    Mayes PA. Intermediary metabolism of fructose. Am J Clin Nutr 1993; 58: 754S-65SGoogle Scholar
  131. 131.
    Reed JM, Brozinick JT, Lee MC, et al. Muscle glycogen storage postexercise: effect of mode of carbohydrate administration. J Appl Physiol 1989l; 66: 720–6PubMedGoogle Scholar
  132. 132.
    Zawadzki KM, Yaspelkis III BB, Ivy JL. Carbohydrate-protein complex increases the rate of muscle glycogen storage after exercise. J Appl Physiol 1992; 72: 1854–9PubMedGoogle Scholar
  133. 133.
    Ivy J. Glycogen resynthesis after exercise: effect of carbohydrate intake. Int J Sports Med 1998; 19: S142–5Google Scholar
  134. 134.
    Rasmussen BB, Tipton KD, Miller SL, et al. An oral essential amino acid-carbohydrate supplement enhances muscle protein anabolism after resistance exercise. J Appl Physiol 2000; 88: 386–92PubMedGoogle Scholar
  135. 135.
    Tipton KD, Ferrando AA, Phillips SM, et al. Postexercise net protein synthesis in human muscle from orally administered amino acids. Am J Physiol 1999; 276: E628–34Google Scholar
  136. 136.
    Tipton KD, Wolfe RR. Protein and amino acids for athletes. J Sports Sci 2004; 22: 65–79PubMedGoogle Scholar
  137. 137.
    Maughan R, Leiper J, Shirreffs S. Factors influencing the restoration of fluid and electrolyte balance after exercise in the heat. Br J Sports Med 1997; 31: 175–82PubMedGoogle Scholar
  138. 138.
    Shirreffs SM, Armstrong AA, Cheuvront SN. Fluid and electrolyte needs for preparation and recovery from training and compitition. J Sports Sci 2004; 22: 57–63PubMedGoogle Scholar
  139. 139.
    Shirreffs SM, Taylor AJ, Leiper JB, et al. Post-exercise rehydration in man: effects of volume consumed and drink sodium content. Med Sci Sports Exerc 1996; 28: 1260–71PubMedGoogle Scholar
  140. 140.
    Costill DL, Sparks KE. Rapid fluid replacement following thermal dehydration. J App Physiol 1973; 34: 299–303Google Scholar
  141. 141.
    Gonzalez-Alonso J, Heaps CL, Coyle EF. Rehydration after exercise with common beverages and water. Int J Sports Med 1992; 13: 399–406PubMedGoogle Scholar
  142. 142.
    Nose H, Mack GW, Shi X, et al. Role of osmolality and plasma volume during rehydration in humans. J Appl Physiol 1988; 65: 325–31PubMedGoogle Scholar
  143. 143.
    Nose H, Mack GW, Shi X, et al. Shift in body fluid compartments after dehydration in humans. J App Physiol 1988; 65: 318–24Google Scholar
  144. 144.
    Maughan RJ, Leiper JB. Sodium intake and post exercise rehydration in man. Eur J App Physiol 1995; 71: 311–9Google Scholar
  145. 145.
    Shirreffs SM. Rehydration and recovery after exercise. In: Maughan RJ, editor. IOC encyclopaedia of sports medicine: nutrition in sport. Oxford: Blackwell Science, 2000: 73–84Google Scholar
  146. 146.
    Maughan RJ, Leiper JB. Post-exercise rehydration in man: effects of voluntary intake of four different beverages. Med Sci Sports Exerc 1993; 25 Suppl.: S2Google Scholar
  147. 147.
    Maughan RJ, Owen JH, Shirreffs SM, et al. Post-exercise rehydration in man: effects of electrolyte addition to ingested fluids. Eur J Appl Physiol 1994; 69: 209–15Google Scholar
  148. 148.
    Costill DL. Sweating: its composition and effects on body fluids. Ann NY Acad Sci 1984; 301: 106–74Google Scholar
  149. 149.
    O’Toole M, Douglas PS. Applied physiology of a triathlon. Sports Med 1995; 19 (4): 251–67PubMedGoogle Scholar
  150. 150.
    Maughan RJ, Leiper JB, Shirreffs SM. Restoration of fluid balance after exercise-indued dehydration: effects of food and fluid intake. Eur J App Physiol 1996; 73: 317–25Google Scholar
  151. 151.
    Armstrong LE, Curtis WC, Hubbard RW, et al. Symptomatic hyponatremia during prolonged exercise in heat. Med Sci Sports Exerc 1993; 25: 543–9PubMedGoogle Scholar
  152. 152.
    Irving RA, Noakes TD, Buck R, et al. Evaluation of renal function and fluid homeostasis during recovery from exercise-induced hyponatremia. J App Physiol 1991; 70: 342–8Google Scholar
  153. 153.
    Speedy DB, Rogers IR, Noakes TD, et al. Diagnosis and prevention of hyponatremia at an ultradistance triathlon. Clin J Sports Med 2000; 10: 52–8Google Scholar
  154. 154.
    Brouns F, Saris WHM, Rehrer NJ. Abdominal complaints and gastrointestinal function during long-lasting exercise. Int J Sports Med 1987; 8: 175–89PubMedGoogle Scholar
  155. 155.
    Rehrer NJ, Brouns F, Beckers EJ, et al. Physiological changes and gastro-intestinal symptoms as a result of ultra-endurance running. Eur J Appl Physiol 1992; 64: 1–8Google Scholar
  156. 156.
    Rehrer NJ, Janssen GME, Brouns F, et al. Fluid intake and gastrointestinal problems in runners competing in a 25-km race and a marathon. Int J Sports Med 1989; 10: S22–5Google Scholar
  157. 157.
    Keeffe EB, Lowe DK, Goss JR, et al. Gastrointestinal symptoms of marathon runners. West J Med 1984; 141: 481–4PubMedGoogle Scholar
  158. 158.
    Riddoch C, Trinick T. Gastrointestinal disturbances in marathon runners. Br J Sports Med 1988; 22: 71–4PubMedGoogle Scholar
  159. 159.
    Sullivan SN. The gastrointestinal symptoms of running [letter]. N Eng J Med 1981; 304: 915Google Scholar
  160. 160.
    Lopez AA, Preziosi JP, Chateau P, et al. Digestive disorders and self medication observed during a competition in endurance athletes: prospective epidemiological study during a championship of triathlon. Gastroenterol Clin Biol 1994; 18: 317–22PubMedGoogle Scholar
  161. 161.
    Jeukendrup AE, Vet-Joop K, Sturk A, et al. Relationship between gastro-intestinal complaints and endotoxaemia, cytokine release and the acute-phase reaction during and after a long-distance triathlon in highly trained men. Clin Sci 2000; 98: 47–55PubMedGoogle Scholar
  162. 162.
    Peters HP, van Schelven WF, Verstappen PA, et al. Exercise performance as a function of semi-solid and liquid carbohydrate feedings during prolonged exercise. Int J Sports Med 1995; 16: 105–13PubMedGoogle Scholar
  163. 163.
    Schaub N, Spichtin HP, Stalder GA. Ischemic colitis as a cause of intestinal bleeding after marathon running [in German]. Schweiz Med Wochenschr 1985; 115: 454–7PubMedGoogle Scholar
  164. 164.
    Øktedalen O, Lunde OC, Opstad PK, et al. Changes in gastro-intestinal mucose after long-distance running. Scand J Gastroenterol 1992; 27: 270–4PubMedGoogle Scholar
  165. 165.
    Bradley SE. Variations in hepatic blood flow in man during health and disease. N Engl J Med 1949; 240: 456–61PubMedGoogle Scholar
  166. 166.
    Clausen JP. Effect of physical training on cardiovascular adjustments to exercise in man. Physiol Rev 1977; 57: 779–815PubMedGoogle Scholar
  167. 167.
    Rowell LB, Blackmon JR, Bruce RA. Indocyanine green clearance and estimated hepatic blood flow during mild to maximal exercise in upright man. J Clin Invest 1964; 43: 1677–90PubMedGoogle Scholar
  168. 168.
    Rowell LB, O’Leary DS, Kellogg DL. Integration of cardiovascular control systems in dynamic exercise. In: Rowell LB, Shephard JT, editors. Handbook of physiology: regulation and integration of multiple systems. New York: Oxford Press, 1996: 770–838Google Scholar
  169. 169.
    van Deventer SJH, Gouma D. Bacterial translocation and endotoxin transmigration in intestinal ischaemia and reperfusion. Curr Opinion Aneasth 1994; 7: 126–30Google Scholar
  170. 170.
    van Leeuwen PA, Boermeester MA, Houdijk AP, et al. Clinical significance of translocation. Gut 1994; 35: S28–34Google Scholar
  171. 171.
    Brock-Utne JG, Gaffin SL, Wells MT, et al. Endotoxaemia in exhausted runners after a long distance race. S Afr Med J 1988; 73: 533–6PubMedGoogle Scholar
  172. 172.
    van Deventer SJH, Buller HR, ten Cate JW, et al. Endotoxaemia: an early predictor of septicaemia in febrile patients. Lancet 1988; I (8586): 605–8Google Scholar
  173. 173.
    Bosenberg AT, Brock-Utne JG, Gaffin SL, et al. Strenuous exercise causes systemic endotoxemia. J Appl Physiol 1988; 65: 106–8PubMedGoogle Scholar
  174. 174.
    Moore GE, Blair Holbein ME, Knochel JP. Exercise-associated collapse in cyclists is unrelated to endotoxemia. Med Sci Sports Med 1995; 27: 1238–42Google Scholar
  175. 175.
    Camus G, Poortmans J, Nys M, et al. Mild endotoxaemia and the inflammatory response induced by exercise. Clin Sci 1997; 92: 415–22PubMedGoogle Scholar
  176. 176.
    Hiller WDB, O’Toole ML, Fortess EE, et al. Medical and physiological considerations in triathlon. Am J Sports Med 1987; 15: 164–7PubMedGoogle Scholar
  177. 177.
    Speedy DB, Noakes TD, Rogers IR, et al. Hyponatremia in ultradistance triathletes. Med Sci Sports Exerc 1999; 31: 809–15PubMedGoogle Scholar
  178. 178.
    Speedy DB, Rogers IR, Noakes TD, et al. Exercise-induced hyponaremia in ultradistance triathletes is caused by inappropriate fluid retention. Clin J Sports Med 2000; 10: 272–8Google Scholar
  179. 179.
    Noakes TD, Goodwin N, Rayner BL, et al. Water intoxication: a possible complication during endurance exercise. Med Sci Sports Exerc 1985; 17: 370–5PubMedGoogle Scholar
  180. 180.
    Vrijens DM, Rehrer NJ. Sodium-free fluid ingestion decreases plasma sodium during exercise in the heat. J Appl Physiol 1999; 86: 1847–51PubMedGoogle Scholar
  181. 181.
    Speedy DB, Thompson JM, Rodgers I, et al. Oral salt supplementation during ultradistance exercise. Clin J Sport Med 2002; 12: 279–84PubMedGoogle Scholar

Copyright information

© Adis Data Information BV 2005

Authors and Affiliations

  • Asker E. Jeukendrup
    • 1
  • Roy L. P. G. Jentjens
    • 1
  • Luke Moseley
    • 1
  1. 1.Human Performance Laboratory, School of Sport and Exercise SciencesUniversity of BirminghamEdgbaston, BirminghamUK

Personalised recommendations