PMID- 17218895
OWN - NLM
STAT- MEDLINE
DCOM- 20070316
LR  - 20161124
IS  - 0195-9131 (Print)
IS  - 0195-9131 (Linking)
VI  - 39
IP  - 1
DP  - 2007 Jan
TI  - Dose-response effects of ingested carbohydrate on exercise metabolism in women.
PG  - 131-8
AB  - PURPOSE: The effect of different quantities of carbohydrate (CHO) intake on CHO 
      metabolism during prolonged exercise was examined in endurance-trained females. 
      METHOD: On four occasions, eight females performed 2 h of cycling at 
      approximately 60% .VO2max with ingestion of beverages containing low (LOW, 0.5 
      g.min(-1)), moderate (MOD, 1.0 g.min(-1)), or high (HIGH, 1.5 g.min(-1)) amounts 
      of CHO, or water only (WAT). Test solutions contained trace amounts of [U-13C] 
      glucose. Indirect calorimetry combined with measurement of expired 13CO2 and 
      plasma 13C enrichment enabled calculation of exogenous CHO, liver-derived 
      glucose, and muscle glycogen oxidation during the last 30 min of exercise. 
      RESULTS: The highest rates of exogenous CHO oxidation were observed in MOD, with 
      no further increases in HIGH (peak rates of 0.33 +/- 0.02, 0.50 +/- 0.03, and 
      0.48 +/- 0.05 g.min(-1) for LOW, MOD, and HIGH, respectively; P < 0.05 for LOW vs 
      MOD and HIGH). Endogenous CHO oxidation was lowest in MOD (0.99 +/- 0.06, 0.82 
      +/- 0.08, 0.70 +/- 0.07, and 0.89 +/- 0.09 g.min(-1); P < 0.05 for MOD vs all 
      other trials). Compared with WAT, CHO ingestion reduced liver glucose oxidation 
      during exercise by approximately 30% (P < 0.05 for WAT vs all CHO). Differential 
      rates of muscle glycogen oxidation were observed with different CHO doses (0.57 
      +/- 0.07, 0.53 +/- 0.08, 0.41 +/- 0.07, and 0.60 +/- 0.09 g.min(-1) for WAT, LOW, 
      MOD, and HIGH respectively; P < 0.05 for MOD vs HIGH). CONCLUSION: In 
      endurance-trained women, the highest rates of exogenous CHO oxidation and 
      greatest endogenous CHO sparing was observed when CHO was ingested at moderate 
      rates (1.0 g.min(-1), 60 g.h(-1)) during exercise.
FAU - Wallis, Gareth A
AU  - Wallis GA
AD  - School of Sport and Exercise Sciences, University of Birmingham, Birmingham, 
      United Kingdom.
FAU - Yeo, Sophie E
AU  - Yeo SE
FAU - Blannin, Andrew K
AU  - Blannin AK
FAU - Jeukendrup, Asker E
AU  - Jeukendrup AE
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Med Sci Sports Exerc
JT  - Medicine and science in sports and exercise
JID - 8005433
RN  - IY9XDZ35W2 (Glucose)
SB  - IM
MH  - Adult
MH  - *Exercise Test
MH  - Female
MH  - Glucose/*administration & dosage
MH  - Humans
MH  - Metabolism/*physiology
MH  - Physical Endurance/physiology
MH  - United Kingdom
EDAT- 2007/01/16 09:00
MHDA- 2007/03/17 09:00
CRDT- 2007/01/16 09:00
PHST- 2007/01/16 09:00 [pubmed]
PHST- 2007/03/17 09:00 [medline]
PHST- 2007/01/16 09:00 [entrez]
AID - 00005768-200701000-00021 [pii]
AID - 10.1249/01.mss.0000241645.28467.d3 [doi]
PST - ppublish
SO  - Med Sci Sports Exerc. 2007 Jan;39(1):131-8. doi: 
      10.1249/01.mss.0000241645.28467.d3.