PMID- 15354036
OWN - NLM
STAT- MEDLINE
DCOM- 20041209
LR  - 20220318
IS  - 0195-9131 (Print)
IS  - 0195-9131 (Linking)
VI  - 36
IP  - 9
DP  - 2004 Sep
TI  - The effect of glucose infusion on glucose kinetics during a 1-h time trial.
PG  - 1543-50
AB  - PURPOSE AND METHODS: To investigate the effect of glucose infusion on glucose 
      kinetics and performance, six endurance cyclists (VO2max = 61.7 +/- 2.0 (mean +/- 
      SE) mL x kg(-1) x min(-1)) completed two performance trials in which they had to 
      accomplish a set amount of work as quickly as possible (991 +/- 41 kJ). Subjects 
      were infused with either glucose (20% in saline; carbohydrate (CHO)) at a rate of 
      1 g x min(-1) or saline (0.9% saline; placebo (PLA)). It was hypothesized that 
      time trial performance would be unaffected by the infusion of glucose, as 
      endogenous stores of CHO would not be limiting in the PLA trial. RESULTS: Plasma 
      glucose concentration increased from 4.8 +/- 0.1 mmol x L(-1) to 5.9 +/- 0.3 mmol 
      x L(-1) during the PLA trial and from 4.9 +/- 0.1 mmol x L(-1) at rest to 12.4 
      +/- 1.1 mmol x L(-1) during the CHO trial. These values were significantly higher 
      at all time points during the CHO trial compared with PLA (P < 0.001). In the 
      final stages of the time trial, Rd in the PLA trial was 49 +/- 5 micromol x 
      kg(-1) x min(-1) compared with 88 +/- 7 micromol x kg(-1) x min(-1) in the CHO 
      trial (P < 0.05). Despite these differences, there was no difference in 
      performance time between PLA and CHO (60.04 +/- 1.47 min, PLA, vs 59.90 +/- 1.49 
      min, CHO, respectively). Infused carbohydrate oxidation in the last 25% of the 
      CHO trial was at least 675 +/- 120 micromol x kg(-1) and contributed 17 +/- 4% to 
      total carbohydrate oxidation. CONCLUSION: The results demonstrate that glucose 
      infusion had no effect on 1-h cycle time-trial performance, despite an increased 
      availability of plasma glucose for oxidation and evidence of increased glucose 
      uptake into the tissues.
FAU - Carter, James M
AU  - Carter JM
AD  - Human Performance Laboratory, School of Sport and Exercise Sciences, The 
      University of Birmingham, Edgbaston, Birmingham, United Kingdom.
FAU - Jeukendrup, Asker E
AU  - Jeukendrup AE
FAU - Mann, Chris H
AU  - Mann CH
FAU - Jones, David A
AU  - Jones DA
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)
RN  - IY9XDZ35W2 (Glucose)
SB  - IM
MH  - Adult
MH  - *Bicycling
MH  - Blood Gas Analysis
MH  - Blood Glucose/*metabolism
MH  - Dietary Carbohydrates/administration & dosage
MH  - Glucose/*administration & dosage
MH  - Heart Rate
MH  - Humans
MH  - Male
MH  - Oxidation-Reduction
MH  - Task Performance and Analysis
MH  - United Kingdom
EDAT- 2004/09/09 05:00
MHDA- 2004/12/16 09:00
CRDT- 2004/09/09 05:00
PHST- 2004/09/09 05:00 [pubmed]
PHST- 2004/12/16 09:00 [medline]
PHST- 2004/09/09 05:00 [entrez]
AID - 00005768-200409000-00013 [pii]
AID - 10.1249/01.mss.0000139892.69410.d8 [doi]
PST - ppublish
SO  - Med Sci Sports Exerc. 2004 Sep;36(9):1543-50. doi: 
      10.1249/01.mss.0000139892.69410.d8.