PMID- 10188743
OWN - NLM
STAT- MEDLINE
DCOM- 19990506
LR  - 20220310
IS  - 0195-9131 (Print)
IS  - 0195-9131 (Linking)
VI  - 31
IP  - 3
DP  - 1999 Mar
TI  - Influence of high and low glycemic index meals on endurance running capacity.
PG  - 393-9
AB  - PURPOSE: The purpose of this study was to examine the effect of high and low 
      glycemic index (GI) carbohydrate (CHO) pre-exercise meals on endurance running 
      capacity. METHODS: Eight active subjects (five male and three female) ran on a 
      treadmill at approximately 70% VO2max to exhaustion on two occasions separated by 
      7 d. Three hours before the run after an overnight fast, each subject was given 
      in a single-blind, random order, isoenergetic meal of 850+/-21 kcal (mean+/-SEM; 
      67% carbohydrate, 30% protein, and 3% fat) containing either high (HGI) or low 
      (LGI) GI carbohydrate foods providing 2.0 g CHO.kg(-1) body weight. RESULTS: 
      Ingestion of the HGI meal resulted in a 580% and 330% greater incremental area 
      under the 3-h blood glucose and serum insulin response curves, respectively. 
      Performance times were not different between the HGI and LGI trials (113+/-4 min 
      and 111+/-5 min, respectively). During the first 80 min of exercise in the LGI 
      trial, CHO oxidation was 12% lower and fat oxidation was 118% higher than in the 
      HGI trial. Although serum insulin concentrations did not differ between trials, 
      blood glucose at 20 min into exercise in the HGI trial was lower than that during 
      the LGI trial at the same time (3.6+/-0.3 mmol.L(-1) vs 4.3+/-0.3 mmol.L(-1); P < 
      0.05). During exercise, plasma glycerol and serum free fatty acid concentrations 
      were lower in the HGI trial than in the LGI trial. CONCLUSIONS: This results 
      demonstrate that although there is a relative shift in substrate utilization from 
      CHO to fat when a low GI meal is ingested before exercise compared with that for 
      a high GI meal, there is no difference in endurance running capacity.
FAU - Wee, S L
AU  - Wee SL
AD  - Department of Physical Education, Sports Science and Recreation Management, 
      Loughborough University, Leicestershire, United Kingdom.
FAU - Williams, C
AU  - Williams C
FAU - Gray, S
AU  - Gray S
FAU - Horabin, J
AU  - Horabin J
LA  - eng
PT  - Clinical Trial
PT  - Journal Article
PT  - Randomized Controlled Trial
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Med Sci Sports Exerc
JT  - Medicine and science in sports and exercise
JID - 8005433
RN  - 0 (Dietary Carbohydrates)
SB  - IM
MH  - Adult
MH  - Dietary Carbohydrates/*administration & dosage
MH  - Female
MH  - Humans
MH  - Male
MH  - Physical Endurance/*physiology
MH  - Running/*physiology
EDAT- 1999/04/03 00:00
MHDA- 1999/04/03 00:01
CRDT- 1999/04/03 00:00
PHST- 1999/04/03 00:00 [pubmed]
PHST- 1999/04/03 00:01 [medline]
PHST- 1999/04/03 00:00 [entrez]
AID - 10.1097/00005768-199903000-00007 [doi]
PST - ppublish
SO  - Med Sci Sports Exerc. 1999 Mar;31(3):393-9. doi: 
      10.1097/00005768-199903000-00007.