PMID- 15155717
OWN - NLM
STAT- MEDLINE
DCOM- 20050418
LR  - 20130926
IS  - 8750-7587 (Print)
IS  - 0161-7567 (Linking)
VI  - 97
IP  - 4
DP  - 2004 Oct
TI  - Effects of carbohydrate supplementation on performance and carbohydrate oxidation 
      after intensified cycling training.
PG  - 1245-53
AB  - 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 approximately 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.
FAU - Halson, Shona L
AU  - Halson SL
AD  - Dept. of Physiology, Australian Institute of Sport, PO Box 176, Belconnen ACT, 
      Australia 2616. shona.halson@ausport.gov.au
FAU - Lancaster, Graeme I
AU  - Lancaster GI
FAU - Achten, Juul
AU  - Achten J
FAU - Gleeson, Michael
AU  - Gleeson M
FAU - Jeukendrup, Asker E
AU  - Jeukendrup AE
LA  - eng
PT  - Clinical Trial
PT  - Journal Article
PT  - Randomized Controlled Trial
PT  - Research Support, Non-U.S. Gov't
DEP - 20040521
PL  - United States
TA  - J Appl Physiol (1985)
JT  - Journal of applied physiology (Bethesda, Md. : 1985)
JID - 8502536
RN  - 0 (Dietary Carbohydrates)
SB  - IM
MH  - Adult
MH  - Bicycling/*physiology
MH  - Cross-Over Studies
MH  - Dietary Carbohydrates/*metabolism
MH  - Dietary Supplements
MH  - Double-Blind Method
MH  - Exercise/*physiology
MH  - Humans
MH  - Male
MH  - Oxidation-Reduction
MH  - Physical Education and Training/methods
MH  - Physical Endurance/*physiology
MH  - Physical Fitness/*physiology
EDAT- 2004/05/25 05:00
MHDA- 2005/04/19 09:00
CRDT- 2004/05/25 05:00
PHST- 2004/05/25 05:00 [pubmed]
PHST- 2005/04/19 09:00 [medline]
PHST- 2004/05/25 05:00 [entrez]
AID - 01368.2003 [pii]
AID - 10.1152/japplphysiol.01368.2003 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 2004 Oct;97(4):1245-53. doi: 
      10.1152/japplphysiol.01368.2003. Epub 2004 May 21.