PMID- 8872656
OWN - NLM
STAT- MEDLINE
DCOM- 19970123
LR  - 20171213
IS  - 8750-7587 (Print)
IS  - 0161-7567 (Linking)
VI  - 81
IP  - 2
DP  - 1996 Aug
TI  - Preexercise glucose ingestion and glucose kinetics during exercise.
PG  - 853-7
AB  - The present study was undertaken to examine the effects of glucose ingestion 
      before exercise on liver glucose output and muscle glucose uptake during 
      exercise. On two occasions, at least 1 wk apart, six trained men (peak pulmonary 
      O2 uptake = 5.11 +/- 0.17 l/min) ingested 400 ml of a solution containing either 
      75 g glucose [carbohydrate (CHO)] or a sweet placebo [control (Con)] 30 min 
      before 60 min of exercise at 71 +/- 1% peak pulmonary O2 uptake. Glucose kinetics 
      (rates of appearance and disappearance) were measured by a primed continuous 
      infusion of [6,6-2H2]glucose. Liver glucose output was derived from total glucose 
      appearance and the appearance of ingested glucose from the gut. After glucose 
      ingestion, plasma glucose increased to 6.4 +/- 0.4 mmol/l immediately before 
      exercise, fell to 4.2 +/- 0.5 mmol/l after 20 min of exercise, and then increased 
      to a higher value than in the Con group (5.4 +/- 0.3 vs. 4.7 +/- 0.1 mmol/l; P < 
      0.05) after 60 min of exercise. In the CHO group, plasma insulin was higher 
      immediately before exercise (P < 0.05) and, despite falling during exercise, 
      remained higher than in the Con group after 60 min of exercise (57.0 +/- 11.4 vs. 
      24.8 +/- 1.7 pmol/l; P < 0.05). The rapid fall in plasma glucose in the CHO group 
      was the result of a higher muscle glucose uptake with the onset of exercise (P < 
      0.05), which could not be matched by the glucose rate of appearance. Liver 
      glucose output was decreased by glucose ingestion, and although it increased 
      during the early stages of exercise in the CHO group, it did not rise above the 
      basal values and was reduced by 62% over the 60 min of exercise compared with the 
      Con group. In summary, preexercise glucose ingestion results in increased muscle 
      glucose uptake and reduced liver glucose output during exercise.
FAU - Marmy-Conus, N
AU  - Marmy-Conus N
AD  - Department of Physiology, Royal Melbourne Hospital, University of Melbourne, 
      Parkville, Victoria, Australia.
FAU - Fabris, S
AU  - Fabris S
FAU - Proietto, J
AU  - Proietto J
FAU - Hargreaves, M
AU  - Hargreaves M
LA  - eng
PT  - Clinical Trial
PT  - Controlled Clinical Trial
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Appl Physiol (1985)
JT  - Journal of applied physiology (Bethesda, Md. : 1985)
JID - 8502536
RN  - 0 (Blood Glucose)
RN  - 0 (Fatty Acids, Nonesterified)
RN  - 0 (Hormones)
RN  - 33X04XA5AT (Lactic Acid)
RN  - IY9XDZ35W2 (Glucose)
SB  - IM
MH  - Adult
MH  - Blood Glucose/*metabolism
MH  - Exercise/*physiology
MH  - Fatty Acids, Nonesterified/blood
MH  - Glucose/pharmacokinetics/*pharmacology
MH  - Hormones/blood
MH  - Humans
MH  - Hyperinsulinism/blood
MH  - Kinetics
MH  - Lactic Acid/blood
MH  - Liver/metabolism
MH  - Male
MH  - Muscle, Skeletal/metabolism
MH  - Oxygen Consumption/physiology
EDAT- 1996/08/01 00:00
MHDA- 1996/08/01 00:01
CRDT- 1996/08/01 00:00
PHST- 1996/08/01 00:00 [pubmed]
PHST- 1996/08/01 00:01 [medline]
PHST- 1996/08/01 00:00 [entrez]
AID - 10.1152/jappl.1996.81.2.853 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 1996 Aug;81(2):853-7. doi: 10.1152/jappl.1996.81.2.853.