The effect of dietary carbohydrate on running performance during a period of intensified training

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The effect of dietary carbohydrate on running performance during a period of intensified training. / Achten, Juul; Halson, S; Moseley, L; Rayson, Mark; Casey, A; Jeukendrup, Asker.

In: Journal of Applied Physiology, Vol. 96, No. 4, 01.01.2004, p. 1331-1340.

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@article{8d44ea23b3374f33a295a0c1ae0b4561,
title = "The effect of dietary carbohydrate on running performance during a period of intensified training",
abstract = "The aim of this study was to determine whether consumption of a diet containing 8.5 g carbohydrate (CHO) . kg(-1) . day(-1) (high CHO; HCHO) compared with 5.4 g CHO . kg(-1) . day(-1) (control; Con) during a period of intensified training ( IT) would result in better maintenance of physical performance and mood state. In a randomized cross-over design, seven trained runners [maximal O-2 uptake ((V) over dot O-2 (max)) 64.7 +/- 2.6 ml . kg(-1) . min(-1)] performed two 11-day trials consuming either the Con or the HCHO diet. The last week of both trials consisted of IT. Performance was measured with a preloaded 8-km all-out run on the treadmill and 16-km all-out runs outdoors. Substrate utilization was measured using indirect calorimetry and continuous [U-C-13] glucose infusion during 30 min of running at 58 and 77% (V) over dot O-2 max. Time to complete 8 km was negatively affected by the IT: time significantly increased by 61 +/- 23 and 155 +/- 38 s in the HCHO and Con trials, respectively. The 16-km times were significantly increased ( by 8.2 +/- 2.1%) during the Con trial only. The Daily Analysis of Life Demands of Athletes questionnaire showed significant deterioration in mood states in both trials, whereas deterioration in global mood scores, as assessed with the Profile of Mood States, was more pronounced in the Con trial. Scores for fatigue were significantly higher in the Con compared with the HCHO trial. CHO oxidation decreased significantly from 1.7 +/- 0.2 to 1.2 +/- 0.2 g/min over the course of the Con trial, which was completely accounted for by a decrease in muscle glycogen oxidation. These findings indicate that an increase in dietary CHO content from 5.4 to 8.5 g CHO . kg(-1) . day(-1) (41 vs. 65% total energy intake, respectively) allowed better maintenance of physical performance and mood state over the course of training, thereby reducing the symptoms of overreaching.",
keywords = "muscle glycogen, overtraining, [U-C-13] glucose",
author = "Juul Achten and S Halson and L Moseley and Mark Rayson and A Casey and Asker Jeukendrup",
year = "2004",
month = jan,
day = "1",
doi = "10.1152/japplphysiol.00973.2003",
language = "English",
volume = "96",
pages = "1331--1340",
journal = "Journal of Applied Physiology",
issn = "8750-7587",
publisher = "American Physiological Society",
number = "4",

}

RIS

TY - JOUR

T1 - The effect of dietary carbohydrate on running performance during a period of intensified training

AU - Achten, Juul

AU - Halson, S

AU - Moseley, L

AU - Rayson, Mark

AU - Casey, A

AU - Jeukendrup, Asker

PY - 2004/1/1

Y1 - 2004/1/1

N2 - The aim of this study was to determine whether consumption of a diet containing 8.5 g carbohydrate (CHO) . kg(-1) . day(-1) (high CHO; HCHO) compared with 5.4 g CHO . kg(-1) . day(-1) (control; Con) during a period of intensified training ( IT) would result in better maintenance of physical performance and mood state. In a randomized cross-over design, seven trained runners [maximal O-2 uptake ((V) over dot O-2 (max)) 64.7 +/- 2.6 ml . kg(-1) . min(-1)] performed two 11-day trials consuming either the Con or the HCHO diet. The last week of both trials consisted of IT. Performance was measured with a preloaded 8-km all-out run on the treadmill and 16-km all-out runs outdoors. Substrate utilization was measured using indirect calorimetry and continuous [U-C-13] glucose infusion during 30 min of running at 58 and 77% (V) over dot O-2 max. Time to complete 8 km was negatively affected by the IT: time significantly increased by 61 +/- 23 and 155 +/- 38 s in the HCHO and Con trials, respectively. The 16-km times were significantly increased ( by 8.2 +/- 2.1%) during the Con trial only. The Daily Analysis of Life Demands of Athletes questionnaire showed significant deterioration in mood states in both trials, whereas deterioration in global mood scores, as assessed with the Profile of Mood States, was more pronounced in the Con trial. Scores for fatigue were significantly higher in the Con compared with the HCHO trial. CHO oxidation decreased significantly from 1.7 +/- 0.2 to 1.2 +/- 0.2 g/min over the course of the Con trial, which was completely accounted for by a decrease in muscle glycogen oxidation. These findings indicate that an increase in dietary CHO content from 5.4 to 8.5 g CHO . kg(-1) . day(-1) (41 vs. 65% total energy intake, respectively) allowed better maintenance of physical performance and mood state over the course of training, thereby reducing the symptoms of overreaching.

AB - The aim of this study was to determine whether consumption of a diet containing 8.5 g carbohydrate (CHO) . kg(-1) . day(-1) (high CHO; HCHO) compared with 5.4 g CHO . kg(-1) . day(-1) (control; Con) during a period of intensified training ( IT) would result in better maintenance of physical performance and mood state. In a randomized cross-over design, seven trained runners [maximal O-2 uptake ((V) over dot O-2 (max)) 64.7 +/- 2.6 ml . kg(-1) . min(-1)] performed two 11-day trials consuming either the Con or the HCHO diet. The last week of both trials consisted of IT. Performance was measured with a preloaded 8-km all-out run on the treadmill and 16-km all-out runs outdoors. Substrate utilization was measured using indirect calorimetry and continuous [U-C-13] glucose infusion during 30 min of running at 58 and 77% (V) over dot O-2 max. Time to complete 8 km was negatively affected by the IT: time significantly increased by 61 +/- 23 and 155 +/- 38 s in the HCHO and Con trials, respectively. The 16-km times were significantly increased ( by 8.2 +/- 2.1%) during the Con trial only. The Daily Analysis of Life Demands of Athletes questionnaire showed significant deterioration in mood states in both trials, whereas deterioration in global mood scores, as assessed with the Profile of Mood States, was more pronounced in the Con trial. Scores for fatigue were significantly higher in the Con compared with the HCHO trial. CHO oxidation decreased significantly from 1.7 +/- 0.2 to 1.2 +/- 0.2 g/min over the course of the Con trial, which was completely accounted for by a decrease in muscle glycogen oxidation. These findings indicate that an increase in dietary CHO content from 5.4 to 8.5 g CHO . kg(-1) . day(-1) (41 vs. 65% total energy intake, respectively) allowed better maintenance of physical performance and mood state over the course of training, thereby reducing the symptoms of overreaching.

KW - muscle glycogen

KW - overtraining

KW - [U-C-13] glucose

UR - http://www.scopus.com/inward/record.url?scp=1642414935&partnerID=8YFLogxK

U2 - 10.1152/japplphysiol.00973.2003

DO - 10.1152/japplphysiol.00973.2003

M3 - Article

C2 - 14660506

VL - 96

SP - 1331

EP - 1340

JO - Journal of Applied Physiology

JF - Journal of Applied Physiology

SN - 8750-7587

IS - 4

ER -