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NAP: Training (2014)
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Assessment
In adult athletes, what is optimal blend of carbohydrates for maximal carbohydrate oxidation during exercise training?
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Conclusion
Based on the limited evidence available, carbohydrate (CHO) oxidation was greater in CHO conditions (glucose and glucose+fructose) compared to water placebo, but no differences between the two CHO blends tested were observed in male cyclists. Exogenous CHO oxidation was greater in the glucose+fructose condition vs. glucose-only in a single study.
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Grade: III
- Grade I means there is Good/Strong evidence supporting the statement;
- Grade II is Fair;
- Grade III is Limited/Weak;
- Grade IV is Expert Opinion Only;
- Grade V is Not Assignable.
- High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
- Moderate (B) means we are moderately confident in the effect estimate;
- Low (C) means our confidence in the effect estimate is limited;
- Very Low (D) means we have very little confidence in the effect estimate.
- Ungraded means a grade is not assignable.
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Evidence Summary: What is the optimal blend of carbohydrates for maximal carbohydrate oxidation?
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Search Plan and Results: NAP: Training 2014
In adult athletes, what effect does training with limited carbohydrate availability have on metabolic adaptations that lead to performance improvements?
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Conclusion
Training with limited carbohydrate (CHO) availability may lead to some metabolic adaptations during training, but did not lead to performance improvements. Based on the evidence examined, while there is insufficient evidence supporting a clear performance effect, training with limited CHO availability impaired training intensity and duration.
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Grade: II
- Grade I means there is Good/Strong evidence supporting the statement;
- Grade II is Fair;
- Grade III is Limited/Weak;
- Grade IV is Expert Opinion Only;
- Grade V is Not Assignable.
- High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
- Moderate (B) means we are moderately confident in the effect estimate;
- Low (C) means our confidence in the effect estimate is limited;
- Very Low (D) means we have very little confidence in the effect estimate.
- Ungraded means a grade is not assignable.
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Evidence Summary: Does training with limited carbohydrate availability cause metabolic adaptations that lead to performance improvements?
- Detail
- Quality Rating Summary
For a summary of the Quality Rating results,
click here.
- Worksheets
- Bartlett JK, Lourhelainen J, Iqbal Z, Cochran AJ, Gibala MJ, Gregson W, Close GL, Drust B, Morton JP. Reduced carbohydrate availability enhances exercise-induced p53 signaling in human skeletal muscle: Implications for mitochondrial biogenesis. Am J Physiol Regul Integ Comp Physiol. 2013; 304: R450-R458.
- Camera DM, West DWD, Burd NA, Phillips SM, Garnham AP, Hawley JA, Coffey VG. Low muscle glycogen concentration does not suppress the anabolic response to resistance exercise. J Appl Physiol. 2012; 113: 206-214.
- Havemann L, West SJ, Goedecke JH, Macdonald IA, St Clair Gibson A, Noakes TD, Lambert EV. Fat adaptation followed by carbohydrate loading compromises high-intensity sprint performance. J Appl Physiol. 2006; 100: 194-202.
- Howarth KR, Philips SM, MacDonald MJ, Richards D, Moreau NA, Gibala MJ. Effect of glycogen availability on human skeletal muscle protein turnover during exercise and recovery, J Appl Physiol. 2010; 109: 431-438.
- Hulston CJ, Venables MC, Mann CH, Martin C, Philp A, Baar K, Jeukendrup AE. Training with low muscle glycogen enhances fat metabolism in well-trained cyclists. Med Sci Sports Exerc. 2010; 42(11): 2,046-2,055.
- Lima-Silva AE, Pires FO, Bertuzzi R, Silva-Cavalcante MD, Oliveira RSF, Kiss MA, Bishop D. Effects of a low or high carbohydrate diet on performance, energy system contribution and metabolic responses during supramaximal exercise. Applied Physiology, Nutrition, and Metabolism, 2013; 38 (9): 928-934.
- Morton JP, Croft L, Bartlett JD, MacLaren DPM, Reilly T, Evans L, McArdle A, Drust B. Reduced carbohydrate availability does not modulate training-induced heat shock protein adaptations but does upregulate oxidative enzyme activity in human skeletal muscle. J Appl Physiol. 2009; 106: 1,513-1,521.
- Psilander N, Frank P, Flockhart M, Sahlin K. Exercise with low glycogen increases PGC-1a gene expression in human skeletal muscle. Eur J Appl Physiol. 2013; 113: 951-963.
- Stellingwerff T, Spriet LL, Watt MJ, Kimber NE, Hargreaves M, Hawley JA, Burke LM. Decreased PDH activation and glycogenolysis during exercise following fat adaptation with carbohydrate restoration. Am J Physiol Endocrinol Metab. 2006; 290: E380-E388.
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Search Plan and Results: NAP: Training 2014
In adult athletes, what effect does consuming high or low glycemic meals or foods have on training related metabolic responses and exercise performance?