| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Human Performance Laboratory, School of Sport and Exercise Sciences, University of Birmingham, Birmingham, United Kingdom
2 Human Performance Laboratory, School of Sport and Exercise Sciences, University of Birmingham, Birmingham, United Kingdom; School of Human Movement Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
3 Optimal Performance Ltd., Bristol, United Kingdom
4 QinetiQ Centre for Human Sciences, Farnborough, United Kingdom
* To whom correspondence should be addressed. E-mail: A.E.Jeukendrup{at}bham.ac.uk.
The main aim of the present study was to determine if consumption of a diet containing 8.5 g CHO.kg-1.d-1 (high CHO;HCHO) compared to 5.4 g CHO.kg-1.d-1 (control;CON) during a period of intensified training would result in better maintenance of physical performance and mood state. In a randomized cross-over design, seven trained runners (VO2max 64.7±2.6 ml.kg-1.min-1) performed two 11-day trials consuming either the CON-diet or the HCHO-diet. The last week of both trials consisted of intensified training. Performance was measured using a pre-loaded 8-km all-out run on the treadmill and 16-km all-out runs outdoors. Mood state was assessed with POMS and DALDA questionnaires. Substrate utilization was measured using indirect calorimetry and a continuous [U-13C]-glucose infusion during 30 min of running at 58%VO2max and at 77%VO2max. Time to complete 8-km was negatively affected by the intensified training, the time significantly increased by 61±23s in the HCHO-trial and by 155±38s in the CON-trial. The 16-km times were significantly increased (by 8.2±2.1%) during the CON diet only. The DALDA questionnaire showed significant changes in mood states in both trials, while the deterioration in global mood scores as assessed with the POMS were more pronounced in the CON-trial. Subjects reported significantly higher scores for fatigue in the CON-trial compared to the HCHO-trial. CHO oxidation decreased significantly from 1.7±0.2 to 1.2±0.2 g.min-1 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 g to 8.5 g CHO.kg-1.d-1 (41%E vs 65%E, respectively) allowed better maintenance of physical performance and mood state over the course of training, thereby reducing the symptoms of overreaching.
This article has been cited by other articles:
|
|
 |
|
  W. K. Yeo, C. D. Paton, A. P. Garnham, L. M. Burke, A. L. Carey, and J. A. Hawley Skeletal muscle adaptation and performance responses to once a day versus twice every second day endurance training regimens J Appl Physiol, November 1, 2008; 105(5): 1462 - 1470. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L Bosquet, S Merkari, D Arvisais, and A E Aubert Is heart rate a convenient tool to monitor over-reaching? A systematic review of the literature Br. J. Sports Med., September 1, 2008; 42(9): 709 - 714. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. De Bock, W. Derave, B. O. Eijnde, M. K. Hesselink, E. Koninckx, A. J. Rose, P. Schrauwen, A. Bonen, E. A. Richter, and P. Hespel Effect of training in the fasted state on metabolic responses during exercise with carbohydrate intake J Appl Physiol, April 1, 2008; 104(4): 1045 - 1055. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. L. Halson, G. I. Lancaster, J. Achten, M. Gleeson, and A. E. Jeukendrup Effects of carbohydrate supplementation on performance and carbohydrate oxidation after intensified cycling training J Appl Physiol, October 1, 2004; 97(4): 1245 - 1253. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
