Explain the relationship between exercise intensity and fat use and why this occurs.

  1. Achten J, Gleeson M, Jeukendrup AE. Determination of the exercise intensity that elicits maximal fat oxidation. Med Sci Sports Exer. 2002;34:92–7.

    Article  Google Scholar 

  2. Achten J, Jeukendrup AE. Maximal fat oxidation during exercise in trained men. Int J Sports Med. 2003;24:603–8.

    CAS  Article  PubMed  Google Scholar 

  3. Astorino TA. Is the ventilatory threshold coincident with maximal fat oxidation during submaximal exercise in women? J Sports Med Phys Fitness. 2000;40(3):209–16.

    CAS  PubMed  Google Scholar 

  4. Bentley D, Newell J, Bishop D. Incremental exercise test design and analysis: implications for performance diagnostics in endurance athletes. Sports Med. 2007;37(7):575–86.

    Article  PubMed  Google Scholar 

  5. Bircher S, Knechtle B. Relationship between fat oxidation and lactate threshold in athletes and obese women and men. J Sports Sci Med. 2004;3(3):174–81.

    PubMed  PubMed Central  Google Scholar 

  6. Billat VL, Hill DW, Pinoteau J, Petit B, Koralsztein JP. Effect of protocol on determination of velocity at VO2max and on its time to exhaustion. Arch Physiol Biochem. 1996;104(3):313–21.

    CAS  Article  PubMed  Google Scholar 

  7. Coyle EF, Coggan AR, Hopper MK, Walters TJ. Determinants of endurance in well-trained cyclists. J Appl Physiol. 1988;64:2622–30.

    CAS  PubMed  Google Scholar 

  8. Dyck DJ, Peters SA, Wendling PS, Chesley A, Hultman E, Spriet LL. Regulation of muscle glycogen phosphorylase activity during intense aerobic cycling with elevated FFA. Am J Physiol. 1996;270(1):116–25.

    Google Scholar 

  9. Dyck DJ, Putman CT, Hegenhauser GJF, Hultman E, Spriet LL. Regulation of fat-carbohydrate interaction in skeletal muscle during intense aerobic cycling. Am J Physiol. 1993;265(6):852–9.

    Google Scholar 

  10. Elia M, Livesey G. Energy expenditure and fuel selection in biological systems: the theory and practice of calculations based on indirect calorimetry and tracer methods. World Rev Nutr Diet. 1992;70:68–131.

    CAS  Article  PubMed  Google Scholar 

  11. Goedecke JH, St Clair GA, Grobler L, Collins M, Noakes TD, Lambert EV. Determinants of the variability in respiratory exchange ratio at rest and during exercise in trained athletes. Am J Physiol Endocrinol Metab. 2000;279(6):1325–34.

    Google Scholar 

  12. Ghosh AK. Anaerobic threshold: its concept and role in endurance sport. Malays J Med Sci. 2004;11(1):24–36.

    PubMed  PubMed Central  Google Scholar 

  13. Hetlelid KJ, Plews DJ, Herold E, Laursen PB, Seiler S. Rethinking the role of fat oxidation: substrate utilization during high-intensity interval training in well-trained and recreationally trained runners. BMJ Open Sport Exerc Med. 2015:e000047. doi:10.1136/bmjsem-2015-000047.

  14. Horowitz FJ, Klein S. Lipid metabolism during endurance exercise. Am J Clin Nutr. 2000;72(2):558–63.

    Google Scholar 

  15. Howley ET, Bassett DR, Welch HG. Criteria for maximal oxygen uptake: review and commentary. Med Sci Sports Exer. 1995;27(9):1292–301.

    CAS  Article  Google Scholar 

  16. Jeukendrup AE. Modulation of carbohydrate and fat utilization by diet, exercise and environment. Biochem Soc Trans. 2003;31(6):1270–3. doi:10.1042/bst0311270.

    CAS  Article  PubMed  Google Scholar 

  17. Jeukendrup AE. Regulation of fat metabolism in skeletal muscle. Ann N Y Acad Sci. 2002;967:217–35.

    CAS  Article  PubMed  Google Scholar 

  18. Jones AM, Doust JH. A 1 % treadmill grade most accurately reflects the energetic cost of outdoors running. J Sport Sci. 1996;14:321–7.

    CAS  Article  Google Scholar 

  19. Maughan JR, Gleeson M. The biochemical basis of sports performance. 2nd ed. Oxford University Press; 2010.

  20. Mickelson TC, Hagerman FC. Anaerobic threshold measurements of elite oarsmen. Med Sci Sports Exer. 1982;14(6):440–4.

    CAS  Article  Google Scholar 

  21. Meyer T, Lucia A, Earnest CO, Kindermann W. A conceptual framework for performance diagnosis and training prescription from submaximal gas exchange parameters—theory and application. Int J Sports Med. 2005;26(1):38–48.

    Article  Google Scholar 

  22. Mooses M, Tippi B, Mooses K, Durussel J, Mäestu J. Better economy in field running than on the treadmill: evidence from high-level distance runners. Biol Sport. 2015;32(2):155–9.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  23. Pierce S, Hahn A, Davie A, Lawton E. Prolonged incremental tests do not necessarily compromise VO2max in well-trained athletes. J Sci Med Sports. 1999;2(4):356–63.

    CAS  Article  Google Scholar 

  24. Rehrer NJ, Wagenmakers AJM, Beckers EJ, Halliday D, Leiper JB, Brouns F, Maughan RJ, Westerterp K, Saris WHM. Gastric emptying, absorption and carbohydrate oxidation during prolonged exercise. J Appl Physiol. 1992;72(2):468–75.

    CAS  PubMed  Google Scholar 

  25. Romijn JA, Coyle EF, Sidossis LS, Zhang XJ, Wolfe RR. Regulation between fatty acid delivery and fatty acid oxidation during strenuous exercise. J Appl Physiol. 1995;79:1939–45.

    CAS  PubMed  Google Scholar 

  26. Rapoport BI. Metabolic factors limiting performance in marathon runners. PLoS Comput Biol. 2010;6(10), e1000960. doi:10.1371/journal.pcbi.1000960.

    Article  PubMed  PubMed Central  Google Scholar 

  27. Sidossis LS, Gastaldelli A, Klein S, Wolfe RR. Regulation of plasma fatty acid oxidation during low- and high-intensity exercise. Am J Physiol. 1997;272(6):1065–70.

    Google Scholar 

  28. Stepto NK, Martin DT, Fallon KE, Hawley JA. Metabolic demands of intense aerobic interval training in competitive cyclists. Med Sci Sports Exer. 2001;33:303–10.

    CAS  Article  Google Scholar 

  29. Van Loon LJC, Paul LG, Constantin TD, Saris WHM, Wagenmakers AJM. The effects of increasing exercise intensity on muscle fuel utilization in humans. J Physiol. 2001;536(1):295–304.

    Article  PubMed  PubMed Central  Google Scholar 


Page 2

  Athletes (n = 30) Non-athletes (n = 17)
Age (year) 25.3 ± 3.2 26.8 ± 3.1
Height (cm) 197 ± 8.6 176.5 ± 6.5
Body mass (kg) 99 ± 6.3 85.6 ± 6.3

  1. Values are expressed as means ± SD
  2. n number of subjects