PMID- 11090571
OWN - NLM
STAT- MEDLINE
DCOM- 20010111
LR  - 20171213
IS  - 8750-7587 (Print)
IS  - 0161-7567 (Linking)
VI  - 89
IP  - 6
DP  - 2000 Dec
TI  - Effects of carbohydrate ingestion before and during exercise on glucose kinetics 
      and performance.
PG  - 2220-6
AB  - We investigated the effect of carbohydrate (CHO) ingestion before and during 
      exercise and in combination on glucose kinetics, metabolism and performance in 
      seven trained men, who cycled for 120 min (SS) at approximately 63% of peak power 
      output, followed by a 7 kJ/kg body wt time trial (TT). On four separate 
      occasions, subjects received either a placebo beverage before and during SS (PP); 
      placebo 30 min before and 2 g/kg body wt of CHO in a 6.4% CHO solution throughout 
      SS (PC); 2 g/kg body wt of CHO in a 25.7% CHO beverage 30 min before and placebo 
      throughout SS (CP); or 2 g/kg body wt of CHO in a 25.7% CHO beverage 30 min 
      before and 2 g/kg of CHO in a 6.4% CHO solution throughout SS (CC). Ingestion of 
      CC and CP markedly (>8 mM) increased plasma glucose concentration ([glucose]) 
      compared with PP and PC (5 mM). However, plasma [glucose] fell rapidly at the 
      onset of SS so that after 80 min it was similar (6 mM) between all treatments. 
      After this time, plasma [glucose] declined in both PP and CP (P < 0.05) but was 
      well maintained in both CC and PC. Ingestion of CC and CP increased rates of 
      glucose appearance (R(a)) and disappearance (R(d)) compared with PP and PC at the 
      onset of, and early during, SS (P < 0.05). However, late in SS, both glucose R(a) 
      and R(d) were higher in CC and PC compared with other trials (P < 0.05). Although 
      calculated rates of glucose oxidation were different when comparing the four 
      trials (P < 0.05), total CHO oxidation and total fat oxidation were similar. 
      Despite this, TT was improved in CC and PC compared with PP (P < 0.05). We 
      conclude that 1) preexercise ingestion of CHO improves performance only when CHO 
      ingestion is maintained throughout exercise, and 2) ingestion of CHO during 120 
      min of cycling improves subsequent TT performance.
FAU - Febbraio, M A
AU  - Febbraio MA
AD  - Exercise Physiology and Metabolism Laboratory, Department of Physiology, The 
      University of Melbourne, Parkville, Victoria 3052, Australia.
FAU - Chiu, A
AU  - Chiu A
FAU - Angus, D J
AU  - Angus DJ
FAU - Arkinstall, M J
AU  - Arkinstall MJ
FAU - Hawley, J A
AU  - Hawley JA
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 (Dietary Carbohydrates)
RN  - IY9XDZ35W2 (Glucose)
SB  - IM
MH  - Adult
MH  - Beverages
MH  - Bicycling
MH  - Blood Glucose/analysis
MH  - Dietary Carbohydrates/administration & dosage/*pharmacology
MH  - Drug Administration Schedule
MH  - Exercise/*physiology
MH  - Glucose/*metabolism
MH  - Humans
MH  - Kinetics
MH  - Male
MH  - Oxidation-Reduction
MH  - Physical Endurance/physiology
EDAT- 2000/11/25 11:00
MHDA- 2001/02/28 10:01
CRDT- 2000/11/25 11:00
PHST- 2000/11/25 11:00 [pubmed]
PHST- 2001/02/28 10:01 [medline]
PHST- 2000/11/25 11:00 [entrez]
AID - 10.1152/jappl.2000.89.6.2220 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 2000 Dec;89(6):2220-6. doi: 10.1152/jappl.2000.89.6.2220.