PMID- 20299609
OWN - NLM
STAT- MEDLINE
DCOM- 20101008
LR  - 20220408
IS  - 1522-1601 (Electronic)
IS  - 0161-7567 (Linking)
VI  - 108
IP  - 6
DP  - 2010 Jun
TI  - Fuel selection and cycling endurance performance with ingestion of [13C]glucose: 
      evidence for a carbohydrate dose response.
PG  - 1520-9
LID - 10.1152/japplphysiol.91394.2008 [doi]
AB  - Endurance performance and fuel selection while ingesting glucose (15, 30, and 60 
      g/h) was studied in 12 cyclists during a 2-h constant-load ride [approximately 
      77% peak O2 uptake] followed by a 20-km time trial. Total fat and carbohydrate 
      (CHO) oxidation and oxidation of exogenous glucose, plasma glucose, glucose 
      released from the liver, and muscle glycogen were computed using indirect 
      respiratory calorimetry and tracer techniques. Relative to placebo (210+/-36 W), 
      glucose ingestion increased the time trial mean power output (%improvement, 90% 
      confidence limits: 7.4, 1.4 to 13.4 for 15 g/h; 8.3, 1.4 to 15.2 for 30 g/h; and 
      10.7, 1.8 to 19.6 for 60 g/h glucose ingested; effect size=0.46). With 60 g/h 
      glucose, mean power was 2.3, 0.4 to 4.2% higher, and 3.1, 0.5 to 5.7% higher than 
      with 30 and 15 g/h, respectively, suggesting a relationship between the dose of 
      glucose ingested and improvements in endurance performance. Exogenous glucose 
      oxidation increased with ingestion rate (0.17+/-0.04, 0.33+/-0.04, and 
      0.52+/-0.09 g/min for 15, 30, and 60 g/h glucose), but endogenous CHO oxidation 
      was reduced only with 30 and 60 g/h due to the progressive inhibition of glucose 
      released from the liver (probably related to higher plasma insulin concentration) 
      with increasing ingestion rate without evidence for muscle glycogen sparing. Thus 
      ingestion of glucose at low rates improved cycling time trial performance in a 
      dose-dependent manner. This was associated with a small increase in CHO oxidation 
      without any reduction in muscle glycogen utilization.
FAU - Smith, JohnEric W
AU  - Smith JW
AD  - Gatorade Sports Science Institute, 617 W. Main St., Barrington, IL 60074, USA. 
      johneric.smith@gatorade.com
FAU - Zachwieja, Jeffrey J
AU  - Zachwieja JJ
FAU - Peronnet, Francois
AU  - Peronnet F
FAU - Passe, Dennis H
AU  - Passe DH
FAU - Massicotte, Denis
AU  - Massicotte D
FAU - Lavoie, Carole
AU  - Lavoie C
FAU - Pascoe, David D
AU  - Pascoe DD
LA  - eng
PT  - Journal Article
DEP - 20100318
PL  - United States
TA  - J Appl Physiol (1985)
JT  - Journal of applied physiology (Bethesda, Md. : 1985)
JID - 8502536
RN  - 0 (Dietary Carbohydrates)
RN  - IY9XDZ35W2 (Glucose)
SB  - IM
MH  - Administration, Oral
MH  - Adult
MH  - Bicycling/*physiology
MH  - Dietary Carbohydrates/*administration & dosage/*metabolism
MH  - Dose-Response Relationship, Drug
MH  - Glucose/*administration & dosage
MH  - Humans
MH  - Male
MH  - Physical Endurance/drug effects/*physiology
MH  - *Task Performance and Analysis
EDAT- 2010/03/20 06:00
MHDA- 2010/10/12 06:00
CRDT- 2010/03/20 06:00
PHST- 2010/03/20 06:00 [entrez]
PHST- 2010/03/20 06:00 [pubmed]
PHST- 2010/10/12 06:00 [medline]
AID - 91394.2008 [pii]
AID - 10.1152/japplphysiol.91394.2008 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 2010 Jun;108(6):1520-9. doi: 
      10.1152/japplphysiol.91394.2008. Epub 2010 Mar 18.