CoChat
Sign Up
Cited by 164Sports Performance and TrainingMuscle metabolism and nutritionCardiovascular and exercise physiology

A signalling role for muscle glycogen in the regulation of pace during prolonged exercise

Open access
Rauch, H G L, St Clair Gibson, A, Lambert, E V, Noakes, T D·2005·British Journal of Sports Medicine
DOI 10.1136/bjsm.2003.010645PMC PMC1725021
Open this paper in CoChat — free accountOpen PDF

Abstract

INTRODUCTION: In this study we examined the pacing strategy and the end muscle glycogen contents in eight cyclists, once when they were carbohydrate loaded and once when they were non-loaded. METHODS: Cyclists completed 2 hours of cycling at approximately 73% of maximum oxygen consumption, which included five sprints at 100% of peak sustained power output every 20 minutes, followed immediately by a 1 hour time trial. Muscle biopsies were performed before and immediately after exercise, while blood samples were taken during the 2 hour steady state rides and immediately after exercise. RESULTS: Carbohydrate loading improved mean power output during the 1 hour time trial (mean (SEM) 219 (17) v 233 (15) W; p<0.05) and enabled subjects to use significantly more muscle glycogen than during the trial following their normal diet. Significantly, the subjects, kept blind to all feedback except for time, started both time trials at similar workloads ( approximately 30 W), but after 1 minute of cycling, the workload average 14 W higher throughout the loaded compared with the non-loaded time trial. There were no differences in subjects' plasma glucose and lactate concentrations and heart rates in the carbohydrate loaded versus the non-loaded trial. Of the eight subjects, seven improved their time trial performance after carbohydrate loading. Finishing muscle glycogen concentrations in these seven subjects were remarkably similar in both trials (18 (3) v 20 (3) mmol/kg w/w), despite significantly different starting values and time trial performances (36.55 (1.47) v 38.14 (1.27) km/h; p<0.05). The intra-subject coefficient of variation (CV) for end glycogen content in these seven subjects was 10%, compared with an inter-subject CV of 43%. CONCLUSIONS: As seven subjects completed the time trials with the same end exercise muscle glycogen concentrations, diet induced changes in pacing strategies during the time trials in these subjects may have resulted from integrated feedback from the periphery, perhaps from glycogen content in exercising muscles.

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 · 10.1136/bjsm.2003.010645

Cites

34 of 34 references verified0 citation errors · 0 not checkable

Statistics

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

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • CHO loading using a similar pattern and amount of carbohydrate intake during the mid-luteal phase fails to change resting muscle glycogen concentrations or only documents a modest increase of 13%, compared to what is generally reported for male athletes (18-47%) or female athletes during the follicular phase (17-31%).

    “CHO loading using a similar pattern and amount of carbohydrate intake during the mid-luteal (ML) phase failed to change resting muscle glycogen concentrations [182] or only documented a modest increase (13%) [186] compared to what is generally reported for male athletes (18–47%) [185,187–191] or female athletes during the follicular phase (17–31%) [184,185].”

    From International society of sports nutrition position stand: nutritional concerns of the female athlete (2023) · cites this paper as [190]

    Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

    Experimental — accuracy not yet measured

  • Rauch et al. proposed that power output is dependent on the brain anticipating the rate of muscle glycogen utilization, leading to individual critical levels of endpoint muscle glycogen.

    “Rauch et al. [34] proposed that the power output developed is dependent on the brain, which anticipates the rate of muscle glycogen utilization leading to individual “critical” levels of endpoint muscle glycogen.”

    From Periodization of carbohydrate intake: short-term effect on performance (2016) · cites this paper as [34]

Self-check

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

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

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Rauch, Gibson, Lambert, et al www.bjsportmed.com on August 15, 2023 by guest. Protected by copyright. http://bjsm.bmj.com/ Br J Sports Med: first published as 10.1136/bjsm.2003.010645 on 23 December 2004. Downloaded from REFERENCES

Cited by

Sorted by citations

Related

Authors
Rauch, H. G. L., St Clair Gibson, A., Lambert, E. V., & Noakes, T. D.
Affiliations
University of Cape Town (ZA)
ORCID
Venue
British Journal of Sports Medicine
Publisher
BMJ
Published
2004-12-23
Volume
39
Issue
1
Pages
34-38
ISSN
  • 0306-3674 (ISSN-L)
  • 1473-0480
DOI
10.1136/bjsm.2003.010645
PMC
PMC1725021
OpenAlex
W2102458927
Cited by
164
References
34
Citations by year
2026: 1 · 2025: 1 · 2024: 1 · 2023: 6 · 2022: 8 · 2021: 3 · 2020: 7 · 2019: 8 · 2018: 6 · 2017: 8 · 2016: 8 · 2015: 9 · 2014: 11 · 2013: 14 · 2012: 4
FWCI
8.06
Type
journal article
Language
en
Open access
Locations
  • British Journal of Sports Medicine (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
Medical Research Council
Topics
  • Health Sciences › Medicine › Orthopedics and Sports Medicine › Sports Performance and Training
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
  • Health Sciences › Medicine › Complementary and alternative medicine › Cardiovascular and exercise physiology
Keywords
muscle glycogen, carbohydrate loading, prolonged exercise, cyclists, time trial performance, output power
MeSH terms
Adult, Bicycling, Biopsy, Blood Glucose, Dietary Carbohydrates, Exercise Test, Glycogen, Heart Rate, Humans, Male, Oxygen Consumption, Physical Endurance, Exercise, Muscle, Skeletal, Lactic Acid

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