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Cited by 76Sports Performance and TrainingMuscle metabolism and nutritionCardiovascular and exercise physiology

Effects of carbohydrate supplementation on performance and carbohydrate oxidation after intensified cycling training

Halson, Shona L., Lancaster, Graeme I., Achten, Juul, Gleeson, Michael, Jeukendrup, Asker E.·2004·Journal of Applied Physiology
DOI 10.1152/japplphysiol.01368.2003
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Abstract

To study the effects of carbohydrate (CHO) supplementation on performance changes and symptoms of overreaching, six male endurance cyclists completed 1 wk of normal (N), 8 days of intensified (ITP), and 2 wk of recovery training (R) on two occasions in a randomized crossover design. Subjects completed one trial with a 6% CHO solution provided before and during training and a 20% solution in the 1 h postexercise (H-CHO trial). On the other occasion, subjects consumed a 2% CHO solution at the same time points (L-CHO). A significant decline in time to fatigue at ∼63% maximal power output (H-CHO: 17 ± 3%; L-CHO: 26 ± 7%) and a significant increase in mood disturbance occurred in both trials after ITP. The decline in performance was significantly greater in the L-CHO trial. After ITP, a significant decrease in estimated muscle glycogen oxidation (H-CHO: N 49.3 ± 2.9 kcal/30 min, ITP 32.6 ± 3.4 kcal/30 min; L-CHO: N 49.1 ± 30 kcal/30 min, ITP 39.0 ± 5.6 kcal/30 min) and increase in fat oxidation (H-CHO: N 16.3 ± 2.4 kcal/30 min, ITP 27.8 ± 2.3 kcal/30 min; L-CHO: N 16.9 ± 2.6 kcal/30 min, ITP: 25.4 ± 3.5 kcal/30 min) occurred alongside significant increases in glycerol and free fatty acids and decreases in free triglycerides in both trials. An interaction effect was observed for submaximal plasma concentrations of cortisol and epinephrine, with significantly greater reductions in these stress hormones in L-CHO compared with H-CHO after ITP. These findings suggest that CHO supplementation can reduce the symptoms of overreaching but cannot prevent its development. Decreased endocrine responsiveness to exercise may be implicated in the decreased performance and increased mood disturbance characteristic of overreaching.

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Crossref · 10.1152/japplphysiol.01368.2003

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  • Carbohydrates reduce symptoms of fatigue and overreaching.

    “reduce symptoms of fatigue and overreaching [64–67]”

    From Periodized Nutrition for Athletes (2017) · cites this paper as [66]

  • These studies used an extreme training volume to simulate a training camp situation, and after 1-2 weeks performance decreased in all groups.

    “However, it must be noted that these studies used an extreme training volume to simulate a training camp situation and the result after 1–2 weeks was a decreased performance in all groups.”

    From Periodized Nutrition for Athletes (2017) · cites this paper as [66]

  • In intensified training studies, carbohydrate supplementation and higher overall carbohydrate intake reduced performance decrements and overreaching symptoms despite more training work.

    “A consistent finding in these studies was that when athletes were supplemented with carbohydrates, and had a higher overall carbohydrate intake, reductions in performance were less profound and the symptoms of overreaching were reduced, despite the fact that they performed more work in training [64, 66].”

    From Periodized Nutrition for Athletes (2017) · cites this paper as [66]

  • In a simulated training camp with 1-2 weeks of intensified training, athletes experienced extreme fatigue and decreased performance by the end of the intensified training period.

    “We simulated a training camp scenario where athletes performed 1–2 weeks of intensified training, resulting in extreme fatigue and decreased performance by the end of the intensified training period [64, 66].”

    From Periodized Nutrition for Athletes (2017) · cites this paper as [66]

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Related

Authors
Halson, S. L., Lancaster, G. I., Achten, J., Gleeson, M., & Jeukendrup, A. E.
ORCID
Venue
Journal of Applied Physiology
Publisher
American Physiological Society
Published
2004-10
Volume
97
Issue
4
Pages
1245-1253
ISSN
  • 0161-7567 (ISSN-L)
  • 8750-7587
  • 1522-1601
DOI
10.1152/japplphysiol.01368.2003
OpenAlex
W2089461548
Cited by
76
References
38
Citations by year
2026: 2 · 2025: 2 · 2024: 4 · 2023: 1 · 2022: 3 · 2021: 1 · 2020: 3 · 2019: 4 · 2018: 3 · 2017: 4 · 2016: 6 · 2015: 8 · 2014: 4 · 2013: 9 · 2012: 4
FWCI
0.98
Type
journal article
Language
en
Open access
closed
Locations
  • Journal of Applied Physiology (publishedVersion)
  • PubMed (publishedVersion)
  • University of Birmingham Research Portal (University of Birmingham) (submittedVersion)
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
carbohydrate supplementation, overtraining, overreaching, endurance cycling, carbohydrate oxidation, muscle glycogen, fat oxidation, mood disturbance, cortisol, epinephrine, time to exhaustion, exercise intensity
MeSH terms
Adult, Bicycling, Dietary Carbohydrates, Double-Blind Method, Humans, Male, Oxidation-Reduction, Physical Education and Training, Physical Endurance, Physical Fitness, Exercise, Cross-Over Studies, Dietary Supplements

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