Abstract
Aim of this study was to examine the effects of a semi-solid and a liquid carbohydrate
feeding on exercise performance. Thirty-two male triathletes performed three exercise
trials (3 hours maximal at 75 % VO2max) with either a semi-solid feeding (S), an iso-caloric liquid feeding (F) or a
liquid placebo (P). Exercise consisted of cycling (bout 1 and 3) and running (bout
2 and 4). Survival analysis revealed that the median maximum test time (MTT) with
F, S and P was 180, 126 and 120 min, respectively. Median MTT was longer with F than
with S (sign-test; p<0.05) or P (p< 0.001), with no difference between S and P. Mean
power output during supra-maximal tests after bout 2 (W1) and at the end of exercise
(Wend) were 371, 365, 362 and 334, 332, 321 W with F, S and P, respectively. Differences
between F and P were significant (p<0.01). Regression analysis identified five variables
that were associated with 93 % of the variance in MTT. The variance in W| was explained
for 83 % by three variables. Wend) was explained (90 %) by three variables. A significant dietary contribution to MTT
and Wend was found, but not to W1, This suggests that the influence of the feedings on performance is different among
performance tests.
Key words
Liquid and solid nutrition - triathletes - running - cycling - energy metabolism -
fluid balance
