Cited by 110Muscle metabolism and nutritionCardiovascular and exercise physiologySports Performance and Training

Carbohydrate supplementation during prolonged cycling exercise spares muscle glycogen but does not affect intramyocellular lipid use

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Stellingwerff, Trent, Boon, Hanneke, Gijsen, Annemie P., Stegen, Jos H. C. H., Kuipers, Harm, van Loon, Luc J. C.·2007·Pflügers Archiv - European Journal of Physiology

Abstract

Using contemporary stable-isotope methodology and fluorescence microscopy, we assessed the impact of carbohydrate supplementation on whole-body and fiber-type-specific intramyocellular triacylglycerol (IMTG) and glycogen use during prolonged endurance exercise. Ten endurance-trained male subjects were studied twice during 3 h of cycling at 63 +/- 4% of maximal O(2) uptake with either glucose ingestion (CHO trial; 0.7 g CHO kg(-1) h(-1)) or without (CON placebo trial; water only). Continuous infusions with [U-(13)C] palmitate and [6,6-(2)H(2)] glucose were applied to quantify plasma free fatty acids (FFA) and glucose oxidation rates and to estimate intramyocellular lipid and glycogen use. Before and after exercise, muscle biopsy samples were taken to quantify fiber-type-specific IMTG and glycogen content. Plasma glucose rate of appearance (R (a)) and carbohydrate oxidation rates were substantially greater in the CHO vs CON trial. Carbohydrate supplementation resulted in a lower muscle glycogen use during the first hour of exercise in the CHO vs CON trial, resulting in a 38 +/- 19 and 57 +/- 22% decreased utilization in type I and II muscle-fiber glycogen content, respectively. In the CHO trial, both plasma FFA R (a) and subsequent plasma FFA concentrations were lower, resulting in a 34 +/- 12% reduction in plasma FFA oxidation rates during exercise (P < 0.05). Carbohydrate intake did not augment IMTG utilization, as fluorescence microscopy revealed a 76 +/- 21 and 78 +/- 22% reduction in type I muscle-fiber lipid content in the CHO and CON trial, respectively. We conclude that carbohydrate supplementation during prolonged cycling exercise does not modulate IMTG use but spares muscle glycogen use during the initial stages of exercise in endurance-trained men.

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  • Consumption of 5-30 g of carbohydrate during and within 30 min after exhaustive, glycogen-depleting exercise will lower hypoglycemia risk and allow for more efficient restoration of muscle glycogen.

    “In such cases, the consumption of 5–30 g of carbohydrate during and within 30 min after exhaustive, glycogen-depleting exercise will lower hypoglycemia risk and allow for more efficient restoration of muscle glycogen ( 31 , 247 ).”

    From Exercise and Type 2 Diabetes (2010) · cites this paper as [247]

    The Discussion (page unavailable) recommends carbohydrate intake from the onset of prolonged exercise to spare muscle glycogen and maintain euglycemia later in exercise. It does not support the specified 5–30 g dose, intake within 30 minutes after exercise, or more efficient postexercise glycogen restoration. (LLM, conf=0.88)

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  • Glycogen sparing was observed during the first hour of cycling when fed carbohydrates.

    “albeit glycogen sparing was also observed during the first hour of cycling when fed carbohydrates [75].”
  • Carbohydrate feeding during exercise may augment exercise performance via multiple mechanisms consisting of muscle glycogen sparing, liver glycogen sparing and maintenance of plasma glucose and carbohydrate oxidation rates.

    “When taken together, it is currently thought that CHO feeding during exercise may therefore augment exercise performance via multiple mechanisms consisting of muscle glycogen sparing [39], liver glycogen sparing [40] and maintenance of plasma glucose and CHO oxidation rates [41].”

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Authors
Stellingwerff, T., Boon, H., Gijsen, A. P., Stegen, J. H. C. H., Kuipers, H., & van Loon, L. J. C.
Affiliations
Maastricht University (NL)
Corresponding author
Stellingwerff, Trent
Venue
Pflügers Archiv - European Journal of Physiology
Published
2007-02-27
Volume
454
Issue
4
Pages
635-647
ISSN
  • 0031-6768 (ISSN-L)
  • 1432-2013
OpenAlex
W2126954014
Cited by
110
References
54
Citations by year
2026: 1 · 2025: 6 · 2024: 2 · 2023: 5 · 2022: 7 · 2021: 10 · 2020: 7 · 2019: 3 · 2018: 11 · 2017: 5 · 2016: 7 · 2015: 7 · 2014: 7 · 2013: 6 · 2012: 4
FWCI
2.20
Type
journal article
Language
en
Open access
Locations
  • Pflügers Archiv - European Journal of Physiology (publishedVersion, cc-by-nc)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • Research Publications (Maastricht University) (publishedVersion, cc-by-nc)
  • Research Publications (Maastricht University) (submittedVersion, other-oa)
Funders
Natural Sciences and Engineering Research Council of Canada
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
  • Health Sciences › Medicine › Complementary and alternative medicine › Cardiovascular and exercise physiology
  • Health Sciences › Medicine › Orthopedics and Sports Medicine › Sports Performance and Training
Keywords
carbohydrate supplementation, muscle glycogen, intramyocellular lipid, endurance exercise, prolonged cycling, glucose ingestion, free fatty acid oxidation, muscle fiber type, endurance-trained men, energy substrate utilization
MeSH terms
Adult, Biopsy, Blood Glucose, Dietary Carbohydrates, Exercise Test, Fatty Acids, Nonesterified, Glycogen, Humans, Insulin, Lactates, Male, Rest, Triglycerides, Exercise, Muscle, Skeletal, Lipid Metabolism

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