Numerous studies have examined optimal amount and ratio of carbohydrate intake during exercise, however only few address the optimal intake strategy, specifically, how much and when carbohydrates should be consumed. Various theories suggest how and why different carbohydrate intake strategies during prolonged exercise, where fatigue due to glycogen depletion would be expected, could lead to improved performance.
The purpose of this master’s thesis was to determine which of the three most commonly used isocaloric carbohydrate intake strategies would result in the best performance after a simulated cycling race. Additionally, we aimed to investigate how different intake strategies would affect fat and carbohydrate oxidation, gastrointestinal comfort, heart rate, and perceived exertion.
Twelve cyclists participated in the study. Each cyclist completed three experimental visits, during which they followed a randomly selected carbohydrate intake strategy while performing a three-hour simulated cycling race. At the end of each simulation they completed two performance tests. Gas exchange data were sampled for three minutes every 30 minutes during the simulated race. At the same time we obtained heart rate, perceived exertion, and gastrointestinal discomfort. Performance data were obtained from a time trial and a time to task failure test.
The analysis revealed no significant differences between the different isocaloric carbohydrate intake strategies in terms of average power during the time trial or time to task failure. There were no significant differences in fat and carbohydrate oxidation, heart rate, perceived exertion, or gastrointestinal discomfort. A slightly higher carbohydrate oxidation rate was observed in decreasing compared to increasing intake strategy, however this difference was not statistically significant.
|
