The Influence of Low Versus High Carbohydrate Diet on a 45-min Strenuous Cycling Exercise

Kavouras, Stavros A.; Troup, John P.; Berning, Jacqueline R.
February 2004
International Journal of Sport Nutrition & Exercise Metabolism;Feb2004, Vol. 14 Issue 1, p62
Academic Journal
To examine the effects of a 3-day high carbohydrate (H-CHO) and low carbohydrate (L-CHO) diet on 45 min of cycling exercise, 12 endurance-trained cyclists performed a 45-min cycling exercise at 82 ± 2% VO[sub2peak] following an overnight fast, after a 6-day diet and exercise control. The 7-day protocol was repeated under 2 randomly assigned dietary trials H-CHO and L-CHO. On days 1-3, subjects consumed a mixed diet for both trials and for days 4-6 consumed isocaloric diets that contained either 600g or 100g of carbohydrates, for the H-CHO and the L-CHO trials, respectively. Muscle biopsy samples, taken from the vastus lateralis prior to the beginning of the 45-min cycling test, indicated that muscle glycogen levels were significantly higher (p < .05) for the H-CHO trial (104.5 ± 9.4 mmol/kg wet wt) when compared to the L-CHO trial (72.2 ± 5.6 mmol/kg wet wt). Heart rate, ratings of perceived exertion, oxygen uptake, and respiratory quotient during exercise were not significantly different between the 2 trials. Serum glucose during exercise for the H-CHO trial significantly increased (p < .05) from 4.5 ± 0.1 mmol · L[sup-1] (pre) to 6.7 ± 0.6 mmol · L (post), while no changes were found for the L-CHO trial. In addition, postexercise serum glucose was significantly greater (p < .05) for the H-CHO trial when compared to the L-CHO trial (H-CHO, 6.7 ± 0.6 mmol · L[sup-1]; L-CHO, 5.2 ± 0.2 mmol · L[sup-1]. No significant changes were observed in serum free fatty acid, triglycerides, or insulin concentration in either trial. The findings suggest that L-CHO had no major effect on 45-min cycling exercise that was not observed with H-CHO when the total energy intake was adequate.


Related Articles

  • Carbohydrate metabolism determinatives does not affect by acute carnitine supplementation combined to heparin injection during submaximal cycling. Mojtaba, Eizadi; Mohsen, Shafiei; Foroozan, Zahedmanesh; Vahid, Imanipour; Davood, Khorshidi // Annals of Biological Research;2012, Vol. 3 Issue 1, p429 

    A number of studies have reported that high free fatty acid (FFA) availability induces decreases carbohydrate oxidation and delay in onset of fatigue. The study objective was to determine whether L-carnitine supplementation combined to heparin injection affect glucose metabolism and aerobic...

  • Strategies to Enhance Fat Utilisation During Exercise. Hawley, J.A.; Brouns, F.; Jeukendrup, A. // Sports Medicine;Apr1998, Vol. 25 Issue 4, p241 

    Compared with the limited capacity of the human body to store carbohydrate (CHO), endogenous fat depots are large and represent a vast source of fuel for exercise. However, fatty acid (FA) oxidation is limited, especially during intense exercise, and CHO remains the major fuel for oxidative...

  • Q+A.  // Runner's World;Feb2007, Vol. 42 Issue 2, p50 

    The article presents a question posed to nutritionist Liz Applegate from a runner interested in how food products containing hydrogenated oils can be advertised as being free of trans fat.

  • Choosing the right carbs & fats. Antonio, Jose // Joe Weider's Muscle & Fitness;Nov97, Vol. 58 Issue 11, p165 

    Provides information from a study conducted by French scientists on the effects of fatty acids and carbohydrates on glucose and insulin response in young men. Examination on the use of four different meals in random order; Discussion on calorie content of the meals; Information on the results...

  • SUGAR VS. FAT. Stoppani, Jim // Joe Weider's Muscle & Fitness;Oct2006, Vol. 67 Issue 10, p84 

    A question and answer is presented related to carbohydrates and their effects on body fat. The questions asks whether fast carbohydrates are more fattening than dietary fat. The answer, provided by medical doctor Jim Stoppani, notes that eating monounsaturated and polyunsaturated fats can help...

  • The effect of dietary saturated fat on endothelial function. Grieger, J. A.; Keogh, J. B.; Noakes, M.; Foster, P. R.; Clifton, P. M. // Asia Pacific Journal of Clinical Nutrition;2004 Supplement, Vol. 13, pS48 

    Background - The impact different dietary fatty acid profiles have on endothelial function is not well understood. Objective - To determine whether diets high in unsaturated fats induce greater endothelial vasodilation compared to diets high in saturated fat (SFA) or carbohydrate (CARB). Design...

  • Breaking News. Applegate, Liz // Runner's World;Sep2000, Vol. 35 Issue 9, p26 

    Discusses the results of a study on the different proportions of fat and carbohydrates for boosting a runner's endurance, speed and power.

  • Milling Around. Sole-Smith, Virginia // Runner's World;Jan2007, Vol. 42 Issue 1, p52 

    The article encourages runners to seek nutritional carbohydrates from alternative grains including quinoa, polenta, and wheat bulgur.

  • add to your cart. Applegate, Liz // Runner's World;Apr2006, Vol. 41 Issue 4, p60 

    The article recommends Christophereggs, which have six times the amount of omega-3 fatty acids as most other brands, to runners.


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics