Adaptation to a Fat-Rich Diet

Effects on Endurance Performance in Humans


The focus of this review is on studies where dietary fat content was manipulated to investigate the potential ergogenic effect of fat loading on endurance exercise performance. Adaptation to a fat-rich diet is influenced by several factors, of which the duration of the adaptation period, the exercise intensity of the performance test and the content of fat and carbohydrate in the experimental diet are the most important.

Evidence is presented that short term adaptation, <6 days, to a fat-rich diet is detrimental to exercise performance. When adaptation to a fat-rich diet was performed over longer periods, studies where performance was tested at moderate intensity, 60 to 80% of maximal oxygen uptake, demonstrate either no difference or an attenuated performance after consumption of a fat-rich compared with a carbohydrate-rich diet. When performance was measured at high intensity after a longer period of adaptation, it was at best maintained, but in most cases attenuated, compared with consuming a carbohydrate-rich diet.

Furthermore, evidence is presented that adaptation to a fat-rich diet leads to an increased capacity of the fat oxidative system and an enhancement of the fat supply and subsequently the amount of fat oxidised during exercise. However, in most cases muscle glycogen storage is compromised, and although muscle glycogen breakdown is diminished to a certain extent, this is probably part of the explanation for the lack of performance enhancement after adaptation to a fat-rich diet.

This is a preview of subscription content, log in to check access.

Table I
Table II
Fig. 1
Table III
Fig. 2


  1. 1.

    Bergström J, Hermansen L, Hultman E, et al. Diet, muscle glycogen and physical performance. Acta Physiol Scand 1967; 71: 140–50

    PubMed  Article  Google Scholar 

  2. 2.

    Bergström J. Muscle electrolytes in man: determined by neutron activation analysis on needle biopsy specimens. A study on normal subjects, kidney patients and patients with chronic diarrhoea. Scand J Clin Lab Invest Suppl 1962; 68: 11–3

    Google Scholar 

  3. 3.

    Sherman WM. Carbohydrates, muscle glycogen, and muscle glycogen supercompensation. In: Williams MH, editor. Ergogenic aids in sport. Champaign (IL): Human Kinetics, 1983: 3–26

    Google Scholar 

  4. 4.

    Conlee RK. Muscle glycogen and exercise endurance: a twenty-year perspective. Exerc Sci Sports Rev 1987; 15: 1–28

    Article  CAS  Google Scholar 

  5. 5.

    Randle PJ, Garland RB, Hales CN, et al. The glucose-fatty acid cycle: its role in insulin sensitivity and the metabolic disturbances of diabetes mellitus. Lancet 1963; I: 785–9

    Article  Google Scholar 

  6. 6.

    Zinker BA, Britz K, Brooks GA. Effects of a 36-hour fast on human endurance and substrate utilization. J Appl Physiol 1990; 69: 1849–55

    PubMed  CAS  Google Scholar 

  7. 7.

    Loy SF, Conlee RK, Winder WW, et al. Effects of 24-hour fast on cycling endurance time at two different intensities. J Appl Physiol 1986; 61: 654–9

    PubMed  CAS  Google Scholar 

  8. 8.

    Maughan RJ, Gleeson M. Influence of a 36 h fast followed by refeeding with glucose, glycerol or placebo on metabolism and performance during prolonged exercise in man. Eur J Appl Physiol 1988; 57: 570–6

    Article  CAS  Google Scholar 

  9. 9.

    Gleeson M, Greenhaff PL, Maughan RJ. Influence of a 24 h fast on high intensity cycle exercise performance in man. Eur J Appl Physiol 1988; 57: 653–9

    Article  CAS  Google Scholar 

  10. 10.

    Hargreaves M, Kiens B, Richter EA. Effect of increased plasma free fatty acid concentrations on muscle metabolism in exercising men. J Appl Physiol 1991; 70: 194–201

    PubMed  CAS  Google Scholar 

  11. 11.

    Vukovich MD, Costill DL, Hickey MS, et al. Effect of fat emulsion infusion and fat feeding on muscle glycogen utilization during cycle exercise. J Appl Physiol 1993; 75: 1513–8

    PubMed  CAS  Google Scholar 

  12. 12.

    Dyck DJ, Putman CT, Heigenhauser GJF, et al. Regulation of fat-carbohydrate interaction in skeletal muscle during intense aerobic cycling. Am J Physiol 1993; 265 (6 Pt 1): E852–9

    PubMed  CAS  Google Scholar 

  13. 13.

    Costill DL, Dalsky GP, Fink WJ. Effects of caffeine ingestion on metabolism and exercise performance. Med Sci Sports Exerc 1978; 10: 155–8

    CAS  Google Scholar 

  14. 14.

    Essig D, Costill DL, Van Handel PJ. Effects of caffeine ingestion on utilization of muscle glycogen and lipid during leg ergometer cycling. Int J Sports Med 1980; I: 86–90

    Article  Google Scholar 

  15. 15.

    Graham TE, Rush JWE, Van Soeren MH. Caffeine and exercise: metabolism and performance. Can J Appl Physiol 1994; 19: 111–138

    PubMed  Article  CAS  Google Scholar 

  16. 16.

    Graham T. Caffeine. Can J Appl Physiol 1998; 23: 323-35

  17. 17.

    Sherman WM, Leenders N. Fat loading: the next magic bullet. Int J Sports Nutr 1995; 5 Suppl.: S1–12

    Google Scholar 

  18. 18.

    Zuntz N. Über die bedeutung der verschiedenen nahrstoffe als erzeuger der muskelkraft. Pflügers Arch 1901; 83: 557–71

    Article  CAS  Google Scholar 

  19. 19.

    Christensen EH, Hansen O. Arbeitsfähigkeit und ernärung. Skand Arch Physiol 1939; 81: 160–71

    Article  Google Scholar 

  20. 20.

    Martin B, Robinson S, Robertshaw D. Influence of diet on leg uptake of glucose during heavy exercise. Am J Clin Nutr 1978; 31: 62–7

    PubMed  CAS  Google Scholar 

  21. 21.

    Galbo H, Holst JJ, Christensen NJ. The effect of different diets and of insulin on the hormonal response to prolonged exercise. Acta Physiol Scand 1979; 10: 19–32

    Article  Google Scholar 

  22. 22.

    Starling RD, Trappe TA, Parcell AC, et al. Effects of diet on muscle triglyceride and endurance performance. J Appl Physiol 1997; 82: 1185–9

    PubMed  CAS  Google Scholar 

  23. 23.

    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 (Lond) 1999; 517: 919–30

    Article  CAS  Google Scholar 

  24. 24.

    Okano G, Sato Y, Takumi Y, et al. Effect of 4h preexercise high carbohydrate and high fat meal ingestion on endurance performance and metabolism. Int J Sports Med 1996; 17: 530–4

    PubMed  Article  CAS  Google Scholar 

  25. 25.

    Okano G, Sato Y, Murata Y. Effect of elevated blood FFA levels on endurance performance after a single fat meal ingestion. Med Sci Sports Exerc 1998; 30: 763–8

    PubMed  Article  CAS  Google Scholar 

  26. 26.

    Whitley HA, Humphreys SM, Campbell IT, et al. Metabolic and performance responses during endurance exercise after high-fat and high-carbohydrate meals. J Appl Physiol 1998; 85: 418–24

    PubMed  CAS  Google Scholar 

  27. 27.

    Pitsiladis YP, Smith I, Maughan RJ. Increased fat availability enhances the capacity of trained individuals to perform prolonged exercise. Med Sci Sports Exerc. 1999; 31: 1570–9

    PubMed  Article  CAS  Google Scholar 

  28. 28.

    Sherman WM. Metabolism of sugars and physical performance. Am J Clin Nutr 1995; 62 (1) Suppl.: 228S–41S

    PubMed  CAS  Google Scholar 

  29. 29.

    Thomas DE, Brotherhood JR, Brand JC. Carbohydrate feeding before exercise: effect of glycemic index. Int J Sports Nutr 1991; 12: 180–6

    Article  CAS  Google Scholar 

  30. 30.

    Pruett EDR. Glucose and insulin during prolonged work stress in men living on different diets. J Appl Physiol 1970; 28: 199–208

    PubMed  CAS  Google Scholar 

  31. 31.

    Phinney SD, Bistrian BR, Evans WJ, et al. The human metabolic response to chronic ketosis without caloric restriction: preservation of submaximal exercise capability with reduced carbohydrate oxidation. Metabolism 1983; 32: 769–76

    PubMed  Article  CAS  Google Scholar 

  32. 32.

    O’Keeffe KA, Keith RE, Wilson GD, et al. Dietary carbohydrate intake and endurance performance of trained female cyclists. Nutr Res 1989; 9: 819–30

    Article  Google Scholar 

  33. 33.

    Williams C, Brewer J, Walker M. The effect of a high carbohydrate diet on running performance during a 30-km treadmill time trial. Eur J Appl Physiol 1992; 65: 18–24

    Article  CAS  Google Scholar 

  34. 34.

    Lambert EV, Speechly DP, Dennis SC, et al. Enhanced endurance in trained cyclists during moderate intensity exercise following 2 weeks adaptation to a high fat diet. Eur J Appl Physiol 1994; 69: 287–93

    Article  CAS  Google Scholar 

  35. 35.

    Muoio DM, Leddy JJ, Horvath PJ, et al. Effects of dietary fat on metabolic adjustments to maximal V̇O2 and endurance in runners. Med Sci Sports Exerc 1994; 26: 81–8

    PubMed  CAS  Google Scholar 

  36. 36.

    Helge JW, Wulff B, Kiens B. Impact of a fat rich diet on endurance in man: role of the dietary period. Med Sci Sports Exerc 1998; 30: 456–61

    PubMed  Article  CAS  Google Scholar 

  37. 37.

    Pogliaghi S, Veicsteinas A. Influence of low and high dietary fat on physical performance in untrained males. Med Sci Sports Exerc 1999; 31: 149–55

    PubMed  Article  CAS  Google Scholar 

  38. 38.

    Goedecke JH, Christie C, Wilson G, et al. Metabolic adaptations to a high-fat diet in endurance cyclists. Metabolism 1999; 48: 1509–17

    PubMed  Article  CAS  Google Scholar 

  39. 39.

    Hermansen L, Hultman E, Saltin B. Muscle glycogen during prolonged severe exercise. Acta Physiol Scand 1967; 71: 129–39

    PubMed  Article  CAS  Google Scholar 

  40. 40.

    Saltin B, Karlsson J. Muscle glycogen utilization during work at different intensities. Adv Exp Med Biol. 1971; 11: 289-99

    Article  CAS  Google Scholar 

  41. 41.

    Romijn JA, Coyle EF, Sidossis LSR, et al. R. Regulation of endogenous fat and carbohydrate metabolism in relation to exercise intensity and duration. Am J Physiol 1993; 265 (3 Pt 1): E380–91

    PubMed  CAS  Google Scholar 

  42. 42.

    Titchenal CA, Gragbill-Yuen RM, Yuen KQ, et al. Effects of a fat-rich diet on maximal oxygen uptake and time-to-exhaustion in female triathletes [abstract no. 1141]. Med Sci Sports Exerc 1998; 30 (5) Suppl.: S201

    Article  Google Scholar 

  43. 43.

    Hetzler RK, Yuen KQ, Graybill-Yuen RM, et al. Effects of fat-rich diet on maximal oxygen uptake and time-to-exhaustion in male triathletes [abstract no. 1142]. Med Sci Sports Exerc 1998; 30 (5 ) Suppl.: S201

    Google Scholar 

  44. 44.

    Helge JW, Richter EA, Kiens B. Interaction of training and diet on metabolism and endurance during exercise in man. J Physiol (Lond) 1996; 292: 293–306

    Google Scholar 

  45. 45.

    Sherman WM. Dietary carbohydrate, muscle glycogen, and exercise performance during 7 d of training. Am J Clin Nutr 1993; 57: 27–31

    PubMed  CAS  Google Scholar 

  46. 46.

    Pitsiladis YP, Maughan RJ. The effects of alterations in dietary carbohydrate intake on the performance of high-intensity exercise in trained individuals. Eur J Appl Physiol 1999; 79: 433–42

    Article  CAS  Google Scholar 

  47. 47.

    Simonsen JC, Sherman WM, Lamb DR, et al. Dietary carbohydrate, muscle glycogen, and power output during rowing training. J Appl Physiol. 1991; 70 (4): 1500–5

    PubMed  CAS  Google Scholar 

  48. 48.

    Pitsiladis YP, Duignan C, Maughan RJ. Effects of alterations in dietary carbohydrate intake on running performance during a 10 km treadmill time trial. Br J Sports Med 1996; 30 (3): 226–31

    PubMed  Article  CAS  Google Scholar 

  49. 49.

    Maughan RJ, Greenhaff PL, Leiper JB, et al. Diet composition and the performance of high-intensity exercise. J Sports Sci 1997; 15: 265–75

    PubMed  Article  CAS  Google Scholar 

  50. 50.

    Larson DE, Hesslink RL, Hrovat MI, et al. Dietary effects on exercising muscle metabolism and performance by 31P-MRS. J Appl Physiol 1994; 77: 1108–15

    PubMed  CAS  Google Scholar 

  51. 51.

    Krogh A, Lindhard J. The relative value of fat and carbohydrate as sources of muscular energy. Biochem J 1920; 14: 290–363

    PubMed  CAS  Google Scholar 

  52. 52.

    Issekutz Jr B, Birkhead NC, Rodahl K. Effect of diet on work metabolism. J Nutr 1963: 79: 109–15

    PubMed  CAS  Google Scholar 

  53. 53.

    Jansson E. On the significance of the respiratory exchange ratio after different diets during exercise in man. Acta Physiol Scand 1982; 114: 103–10

    PubMed  Article  CAS  Google Scholar 

  54. 54.

    Helge JW, Kiens B. Muscle enzyme activity in man: role of substrate availability and training. Am J Physiol 1997; 272 (5 Pt 2): R1620–4

    PubMed  CAS  Google Scholar 

  55. 55.

    Fisher EC, Evans WJ, Phinney SD, et al. Changes in skeletal muscle metabolism induced by a eucaloric ketogenic diet. In: Knuttgen HG, Vogel JA, Portman J, editors. Biochemistry of exercise. Champaign (IL): Human Kinetics, 1983: 497–501

    Google Scholar 

  56. 56.

    Putman CT, Spriet LL, Hultman E, et al. Pyruvate dehydrogenase activity and acetyl group accumulation during exercise after different diets. Am J Physiol 1993; 265 (5 Pt 1): E752–60

    PubMed  CAS  Google Scholar 

  57. 57.

    Cutler DL, Gray CG, Park SW, et al. Low-carbohydrate diet alters intracellular glucose metabolism but not overall glucose disposal in exercise-trained subjects. Metabolism 1995; 44: 1264–70

    PubMed  Article  CAS  Google Scholar 

  58. 58.

    Peters SJ, St Amand TA, Howlett RA, et al. Human skeletal muscle pyruvate dehydrogenase kinase activity increases after a low-carbohydrate diet. Am J Physiol 1982; 275: E980–6

    Google Scholar 

  59. 59.

    Jansson E, Kaijser L. Effect of diet on muscle glycogen and blood glucose utilization during short-term exercise in man. Acta Physiol Scand 1982; 115: 341–7

    PubMed  Article  CAS  Google Scholar 

  60. 60.

    Hultman E, Nilsson L. Liver glycogen in man: effect of different diets and muscular exercise. In: Pernow B, Saltin B, editors. Muscle metabolism during exercise. New York: Plenum, 1971: 143–51

    Google Scholar 

  61. 61.

    Madsen K, Pedersen PK, Rose P, et al. Carbohydrate supercompensation and muscle glycogen utilization during exhaustive running in highly trained athletes. Eur J Appl Physiol 1990; 61: 467–72

    Article  CAS  Google Scholar 

  62. 62.

    Hulsmann WC. Abnormal stress reactions after feeding diets rich in (very) long chain fatty acids: high levels of corticosterone and testosterone. Mol Cell Endocrinol 1978; 12: 1–8

    PubMed  Article  CAS  Google Scholar 

  63. 63.

    Pascoe WS, Smythe GA, Storlien LH. Enhanced responses to stress induced by fat-feeding in rats: relationship between hypothalamic noradrenaline and blood glucose. Brain Res 1991; 550: 192–6

    PubMed  Article  CAS  Google Scholar 

  64. 64.

    McClellan WS, DuBois EF. Prolonged meat diets with a study of kidney function and ketosis. J Biol Chem 1930; 87: 669–80

    CAS  Google Scholar 

  65. 65.

    Cox CM, Brown RC, Mann JI. The effects of high-carbohydrate versus high-fat dietary advice on plasma lipids, lipoproteins, apolipoproteins, and performance in endurance trained cyclists. Nutr Metab Cardiovasc Disease 1996; 6: 227–33

    CAS  Google Scholar 

  66. 66.

    Brown RC, Cox CM. Effects of high fat versus high carbohydrate diets on plasma lipids and lipoproteins in endurance athletes. Med Sci Sports Exerc 1998; 30: 1677–83

    PubMed  Article  CAS  Google Scholar 

  67. 67.

    Leddy J, Horvath P, Rowland J, et al. Effect of a high or a low fat diet on cardiovascular risk factors in male and female runners. Med Sci Sports Exerc 1997; 29: 17–25

    PubMed  CAS  Google Scholar 

  68. 68.

    Phinney SD, Bistrian BR, Wolfe RR, et al. The human metabolic response to chronic ketosis without restriction: physical and biochemical adaptation. Metabolism 1983; 32: 757–68

    PubMed  Article  CAS  Google Scholar 

  69. 69.

    Keith RE, O’Keeffe KA, Blessing DL, et al. Alterations in dietary carbohydrate, protein, and fat intake and mood state in trained female cyclists. Med Sci Sports Exerc 1991; 212–6

    Google Scholar 

Download references


I would like to express gratitude to Dr Bente Kiens and Professor Dr Erik A. Richter for providing the opportunity to perform studies investigating fat diet adaptation and exercise performance in humans at the August Krogh Institute in Copenhagen. Funding was supplied by the Danish National Research Foundation grant No. 504-14, the Danish Research Academy, Team Danmark and the Danish Sports Research Council.

Author information



Corresponding author

Correspondence to Dr Jørn Wulff Helge.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Helge, J.W. Adaptation to a Fat-Rich Diet. Sports Med 30, 347–357 (2000).

Download citation


  • Exercise Intensity
  • Endurance Performance
  • Muscle Glycogen
  • Moderate Exercise Intensity
  • Short Term Adaptation