PMID- 8781194
OWN - NLM
STAT- MEDLINE
DCOM- 19961107
LR  - 20190726
IS  - 0031-6768 (Print)
IS  - 0031-6768 (Linking)
VI  - 432
IP  - 6
DP  - 1996 Oct
TI  - Fuel substrate turnover and oxidation and glycogen sparing with carbohydrate 
      ingestion in non-carbohydrate-loaded cyclists.
PG  - 1003-10
AB  - This study examined the effects of ingesting 500 ml/h of either a 10% 
      carbohydrate (CHO) drink (CI) or placebo (PI) on splanchnic glucose appearance 
      rate (endogenous + exogenous) (Ra), plasma glucose oxidation and muscle glycogen 
      utilisation in 17, non-carbohydrate-loaded, male, endurance-trained cyclists who 
      rode for 180 min at 70% of maximum oxygen uptake. Mean muscle glycogen content at 
      the start of exercise was 130 +/- 6 mmol/kg ww; (mean +/- SEM). Total CHO 
      oxidation was similar in CI and PI subjects and declined during the trial. Ra 
      increased significantly during the trial (P < 0.05) in both groups. Plasma 
      glucose oxidation also increased significantly during the trial, reaching a 
      plateau in the PI subjects, but was significantly (P < 0.05) higher in CI than PI 
      subjects at the end of exercise [(98 +/- 14 vs. 72 +/- 10 micromol/min/kg 
      fat-free mass) (FFM) (1.34 +/- 0.19 vs. 0.93 +/- 0. 13 g/min)]. However, mean 
      endogenous Ra was significantly (P < 0.05) lower in the CI than PI subjects 
      throughout exercise (35 +/- 7 vs. 54 +/- 6 micromol/min/kg FFM), as was the 
      oxidation of endogenous plasma glucose, which remained almost constant in CI 
      subjects, and reached values at the end of exercise of 42 +/- 13 and 72 +/- 10 
      micromol/min/kg FFM in the CI and PI groups respectively. Of the 150 g CHO 
      ingested during the trial, 50% was oxidised. Muscle glycogen disappearance was 
      identical during the first 2 h of exercise in both groups and continued at the 
      same rate in PI subjects, however no net muscle glycogen disappearance occurred 
      during the final hour in CI subjects. We conclude that ingestion of 500 ml/h of a 
      10% CHO solution during prolonged exercise in non carbohydrate loaded subjects 
      has a marked liver glycogen-sparing effect or causes a reduction in 
      gluconeogenesis, or both, maintains plasma glucose concentration and has a muscle 
      glycogen-sparing effect.
FAU - Bosch, A N
AU  - Bosch AN
AD  - The MRC/UCT Bioenergetics of Exercise Research Unit, Department of Physiology, 
      Sports Science Institute of South Africa, University of Cape Town, Boundary Road, 
      Newlands 7925, South Africa.
FAU - Weltan, S M
AU  - Weltan SM
FAU - Dennis, S C
AU  - Dennis SC
FAU - Noakes, T D
AU  - Noakes TD
LA  - eng
PT  - Clinical Trial
PT  - Controlled Clinical Trial
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Germany
TA  - Pflugers Arch
JT  - Pflugers Archiv : European journal of physiology
JID - 0154720
RN  - 0 (Blood Glucose)
RN  - 0 (Dietary Carbohydrates)
RN  - 9005-79-2 (Glycogen)
SB  - IM
MH  - Adult
MH  - Beverages
MH  - *Bicycling
MH  - Blood Glucose/metabolism
MH  - Dietary Carbohydrates/*administration & dosage/metabolism
MH  - *Energy Metabolism
MH  - Exercise/*physiology
MH  - Glycogen/*metabolism
MH  - Humans
MH  - Kinetics
MH  - Male
MH  - Muscles/metabolism
MH  - Oxidation-Reduction
MH  - Oxygen Consumption
MH  - Physical Endurance
EDAT- 1996/10/01 00:00
MHDA- 1996/10/01 00:01
CRDT- 1996/10/01 00:00
PHST- 1996/10/01 00:00 [pubmed]
PHST- 1996/10/01 00:01 [medline]
PHST- 1996/10/01 00:00 [entrez]
AID - 10.1007/s004240050228 [doi]
PST - ppublish
SO  - Pflugers Arch. 1996 Oct;432(6):1003-10. doi: 10.1007/s004240050228.