PMID- 9624641
OWN - NLM
STAT- MEDLINE
DCOM- 19980814
LR  - 20190831
IS  - 0195-9131 (Print)
IS  - 0195-9131 (Linking)
VI  - 30
IP  - 6
DP  - 1998 Jun
TI  - Pre-exercise carbohydrate ingestion: effect of the glycemic index on endurance 
      exercise performance.
PG  - 844-9
AB  - PURPOSE: This study aimed to examine the effect of glycemic index of pre-exercise 
      carbohydrate (CHO) ingestion on exercise metabolism and performance. METHODS: 
      Eight endurance trained men ingested a high glycemic index (HGI), low glycemic 
      index (LGI), or a placebo (CON) meal 45 min before exercise and then cycled for 
      50 min at 67% VO2max. Subjects subsequently performed a 15-min self-paced 
      performance ride in which total work (kJ) was recorded. RESULTS: Plasma glucose 
      concentrations were higher (P < 0.01) after ingestion in HGI compared with LGI 
      and CON (7.53 +/- 0.64 vs 5.55 +/- 0.21 and 4.65 +/- 0.14 mmol.L-1 for HGI, LGI, 
      and CON, respectively, 30 min postprandial; mean +/- SE) but declined at the 
      onset of exercise and were lower (P < 0.01) compared with LGI and CON (4.03 +/- 
      0.31 vs 4.64 +/- 0.24 and 5.09 +/- 0.16 mmol.L-1 for HGI, LGI, and CON 
      respectively; mean +/- SE) at 10 min of exercise. Plasma glucose remained 
      depressed (P < 0.01) until 30 min into exercise in HGI compared with other 
      trials. Plasma insulin concentrations were higher (P < 0.01) following ingestion 
      during rest and exercise in HGI compared with LGI and CON. Plasma FFA 
      concentrations were lower (P < 0.05) following ingestion in HGI and LGI compared 
      with CON and higher (P < 0.05) in LGI compared with HGI at the start and end of 
      exercise. RER and CHO oxidation was higher (P < 0.01) in HGI compared with LGI 
      and CON during submaximal exercise. There were no differences in work output 
      during the performance cycle. CONCLUSIONS: These data indicate that pre-exercise 
      CHO feedings with varying glycemic indexes do not affect exercise performance 
      following short term submaximal exercise despite alterations in metabolism.
FAU - Sparks, M J
AU  - Sparks MJ
AD  - Department of Physical Education and Recreation, Victoria University of 
      Technology, Footscray, Australia.
FAU - Selig, S S
AU  - Selig SS
FAU - Febbraio, M A
AU  - Febbraio MA
LA  - eng
PT  - Clinical Trial
PT  - Controlled Clinical Trial
PT  - Journal Article
PL  - United States
TA  - Med Sci Sports Exerc
JT  - Medicine and science in sports and exercise
JID - 8005433
RN  - 0 (Blood Glucose)
RN  - 0 (Dietary Carbohydrates)
SB  - IM
MH  - Adult
MH  - Blood Glucose/metabolism
MH  - *Dietary Carbohydrates
MH  - Eating
MH  - Exercise/*physiology
MH  - Humans
MH  - Male
MH  - Oxygen Consumption
MH  - Physical Endurance/*physiology
EDAT- 1998/06/13 00:00
MHDA- 1998/06/13 00:01
CRDT- 1998/06/13 00:00
PHST- 1998/06/13 00:00 [pubmed]
PHST- 1998/06/13 00:01 [medline]
PHST- 1998/06/13 00:00 [entrez]
AID - 10.1097/00005768-199806000-00011 [doi]
PST - ppublish
SO  - Med Sci Sports Exerc. 1998 Jun;30(6):844-9. doi: 
      10.1097/00005768-199806000-00011.