Carbohydrate and exercise performance: the role of multiple transportable carbohydrates.

School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, Birmingham, UK.
Current opinion in clinical nutrition and metabolic care 07/2010; 13(4):452-7. DOI: 10.1097/MCO.0b013e328339de9f
Source: PubMed

ABSTRACT Carbohydrate feeding has been shown to be ergogenic, but recently substantial advances have been made in optimizing the guidelines for carbohydrate intake during prolonged exercise.
It was found that limitations to carbohydrate oxidation were in the absorptive process most likely because of a saturation of carbohydrate transporters. By using a combination of carbohydrates that use different intestinal transporters for absorption it was shown that carbohydrate delivery and oxidation could be increased. Studies demonstrated increases in exogenous carbohydrate oxidation rates of up to 65% of glucose: fructose compared with glucose only. Exogenous carbohydrate oxidation rates reach values of 1.75 g/min whereas previously it was thought that 1 g/min was the absolute maximum. The increased carbohydrate oxidation with multiple transportable carbohydrates was accompanied by increased fluid delivery and improved oxidation efficiency, and thus the likelihood of gastrointestinal distress may be diminished. Studies also demonstrated reduced fatigue and improved exercise performance with multiple transportable carbohydrates compared with a single carbohydrate.
Multiple transportable carbohydrates, ingested at high rates, can be beneficial during endurance sports in which the duration of exercise is 3 h or more.

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