PMID- 19574614
OWN - NLM
STAT- MEDLINE
DCOM- 20090813
LR  - 20191111
IS  - 1526-484X (Print)
IS  - 1526-484X (Linking)
VI  - 19
IP  - 3
DP  - 2009 Jun
TI  - No placebo effect from carbohydrate intake during prolonged exercise.
PG  - 275-84
AB  - The purpose of this study was to investigate the possibility of a placebo effect 
      from carbohydrate (CHO) intake during prolonged exercise. Ten endurance-trained 
      male cyclists performed 3 experimental trials consisting of 120 min of 
      steady-state cycling at 61% VO2max followed by a time trial (TT) lasting 
      approximately 60 min. During exercise participants ingested either plain water 
      (WAT), artificially colored and flavored water (PLA), or a 6% 
      carbohydrate-electrolyte solution (CES). PLA and CES were produced with identical 
      color and taste. To investigate the possibility of a placebo effect from CHO 
      intake, participants were told that both flavored solutions contained CHO and 
      that the purpose of the study was to compare CHO drinks with water. Mean power 
      output during TT was 218 +/- 22 W in WAT, 219 +/- 17 W in PLA, and 242 +/- 27 W 
      in CES. Performance times were 66.35 +/- 6.15, 65.94 +/- 5.56, and 59.69 +/- 2.87 
      min for WAT, PLA, and CES, respectively. Therefore, CES ingestion enhanced TT 
      performance by 11.3% compared with WAT (p < .05) and 10.6% compared with PLA (p < 
      .05), with no difference between PLA and WAT. In conclusion, during a prolonged 
      test of cycling performance, in which participants were not fully informed of the 
      test conditions, there was no placebo effect when participants believed they had 
      ingested CHO. In contrast, the real effect of CHO intake was a 10.6% improvement 
      in TT cycling performance.
FAU - Hulston, Carl J
AU  - Hulston CJ
AD  - School of Sport and Exercise Sciences, University of Birmingham, Birmingham, UK.
FAU - Jeukendrup, Asker E
AU  - Jeukendrup AE
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Int J Sport Nutr Exerc Metab
JT  - International journal of sport nutrition and exercise metabolism
JID - 100939812
RN  - 0 (Blood Glucose)
RN  - 0 (Dietary Carbohydrates)
RN  - 33X04XA5AT (Lactic Acid)
SB  - IM
MH  - Adult
MH  - Area Under Curve
MH  - Blood Glucose/metabolism
MH  - Cross-Over Studies
MH  - Dietary Carbohydrates/*administration & dosage
MH  - Humans
MH  - Lactic Acid/blood
MH  - Male
MH  - Nutritional Requirements
MH  - Oxidation-Reduction
MH  - Oxygen Consumption
MH  - Physical Endurance/*drug effects/*physiology
MH  - *Placebo Effect
EDAT- 2009/07/04 09:00
MHDA- 2009/08/14 09:00
CRDT- 2009/07/04 09:00
PHST- 2009/07/04 09:00 [entrez]
PHST- 2009/07/04 09:00 [pubmed]
PHST- 2009/08/14 09:00 [medline]
AID - 10.1123/ijsnem.19.3.275 [doi]
PST - ppublish
SO  - Int J Sport Nutr Exerc Metab. 2009 Jun;19(3):275-84. doi: 
      10.1123/ijsnem.19.3.275.