Student or educator? Sign up with your school email and get 6 months of Pro free.
CoChat
Sign Up
Cited by 294

The DOI matches its Crossref record.

1 Carbohydrate Ingestion During Prolonged Exercise: Effects on Metabolism and Performance

COGGAN, ANDREW R., COYLE, EDWARD F.·1991·Exercise and Sport Sciences Reviews
DOI 10.1249/00003677-199101000-00001
Open this paper in CoChat — free account

Abstract

It is well recognized that energy from CHO oxidation is required to perform prolonged strenuous (greater than 60% VO2 max) exercise. During the past 25 years, the concept has developed that muscle glycogen is the predominant source of CHO energy for strenuous exercise; as a result, the potential energy contribution of blood glucose has been somewhat overlooked. Although during the first hour of exercise at 70-75% VO2max, most of the CHO energy is derived from muscle glycogen, it is clear that the contribution of muscle glycogen decreases over time as muscle glycogen stores become depleted, and that blood glucose uptake and oxidation increase progressively to maintain CHO oxidation (Fig. 1.7). We theorize that over the course of several hours of strenuous exercise (i.e., 3-4 h), blood glucose and muscle glycogen contribute equal amounts of CHO energy, making blood glucose at least as important as muscle glycogen as a CHO source. During the latter stages of exercise, blood glucose can potentially provide all of the CHO energy needed to support exercise at 70-75% VO2max if blood glucose availability is maintained. During prolonged exercise in the fasted state, however, blood glucose concentration often decreases owing to depletion of liver glycogen stores. This relative hypoglycemia, although only occasionally severe enough to result in fatigue from neuroglucopenia, causes fatigue by limiting blood glucose (and therefore total CHO) oxidation. The primary purpose of CHO ingestion during continuous strenuous exercise is to maintain blood glucose concentration and thus CHO oxidation and exercise tolerance during the latter stages of prolonged exercise. CHO feeding throughout continuous exercise does not alter muscle glycogen use. It appears that blood glucose must be supplemented at a rate of approximately 1 g/min late in exercise. Feeding sufficient amounts of CHO 30 minutes before fatigue is as effective as ingesting CHO throughout exercise in maintaining blood glucose availability and CHO oxidation late in exercise. Most persons should not wait, however, until they are fatigued before ingesting CHO, because it appears that glucose entry into the blood does not occur rapidly enough at this time. It also may be advantageous to ingest CHO throughout intermittent or low-intensity exercise rather than toward the end of exercise because of the potential for glycogen synthesis in resting muscle fibers. Finally, CHO ingestion during prolonged strenuous exercise delays by approximately 45 minutes but does not prevent fatigue, suggesting that factors other than CHO availability eventually cause fatigue.

Overview

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1249/00003677-199101000-00001

Cites

Statistics

Verification

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Citations

Cited by

Metadata

Authors
COGGAN, A. R., & COYLE, E. F.
Venue
Exercise and Sport Sciences Reviews
Publisher
Ovid Technologies (Wolters Kluwer Health)
Published
1991-01
Volume
19
Issue
1
Pages
1???40
ISSN
0091-6331 (ISSN-L)
DOI
10.1249/00003677-199101000-00001
OpenAlex
W2014557212
Cited by
294
References
0
FWCI
1.88
Type
journal article
Language
en
Open access
closed

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review

Data sources

Bibliographic data: Semantic Scholar, OpenAlex, Crossref.

Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).

Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.