No effect of carbohydrate feeding on 16 km cycling time trial performance
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Date
2008-11-24Author
Jeukendrup, Asker E.
Hopkins, Shaun
Aragón Vargas, Luis Fernando
Hulston, Carl
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Show full item recordAbstract
The aim of this study is to investigate the
effects of CHO ingestion during high intensity exercise
performance lasting approximately 25 min. Twelve
endurance trained male cyclists (age 19–41 years; body
mass 73.2 ± 4.2 kg; VO2max 66.4 ± 6.2 ml kg-1 min-1)
completed a simulated 16 km time trial (457 ± 37 kJ) time
trial in the lab on three occasions. Once they received a 6%
carbohydrate electrolyte solution (CHO) and twice they
received the same electrolyte containing placebo drink
(PLA). Carbohydrate or placebo drinks were ingested
5 min before the start (4 ml kg-1) and at 25, 50, and 75%
of completion of the time trial (1.4 ml kg-1). The CHO
drink was a 6% sucrose–glucose–electrolyte solution. No
differences were observed in the time to complete the time
trials with either treatment. Time in min:s were
25:30 ± 1:34 and 25:27 ± 1:46 for the two placebo trials
and 25:38 ± 1:59 in the CHO trial. Power output during
the time trials was also remarkably similar: 300 ± 37 W,
301 ± 39 W and 299 ± 40 W, respectively. Pacing strategies
and heart rate were identical in all three trials. From
the two placebo trials, a coefficient of variation for this
performance task was calculated to be 1.1%. Data from this
study provides evidence that carbohydrate ingestion during
short high intensity exercise (*30 min, 85–90% VO2max)
does not improve performance. Furthermore, this study
found a very low coefficient of variation (1.1%) for a
simulated 16 km time trial.
External link to the item
10.1007/s00421-008-0838-zCollections
- Nutrición [252]