The effect of carbohydrate-electrolyte beverage drinking strategy on 10 mile running performance.

The purpose of the present investigation was to investigate the influence of ingesting a carbohydrate-electrolyte beverage ad-libitum or as a prescribed volume on 10 mile run performance and gastrointestinal discomfort. Nine male recreational runners completed the 10 mile run under the following three conditions (1) no drinking (ND; 0 ml, 0 g carbohydrate), (2) ad-libitum drinking (AD; 315 ± 123 ml, 19 ± 7 g carbohydrate) and (3) prescribed drinking (PD; 1055 ± 90 ml, 64 ± 5 g carbohydrate) strategy. During the ad-libitum and prescribed drinking trials, drinks were provided on completion of mile 2, 4, 6 and 8. Running performance, speed (km/hr) and 10 mile run time, were assessed using a global positioning satellite system. The runner's ratings of perceived exertion and gastrointestinal comfort were recorded on completion of each lap of the 10 mile run. There was a significant difference (P<0.10) in the performance times for 10 mile race for the ND, AD and PD trials which were 72:05 ± 3:36 min:s; 71:14 ± 3:35 min:s and 72:12 ± 3.53 min:s respectively (P = 0.094). Ratings of gastrointestinal comfort were reduced during the PD trial, in comparison to both AD and ND trials. In conclusion, runners unaccustomed to habitually drinking carbohydrate-electrolyte beverages during training improved their 10 mile race performance with ad-libitum drinking a carbohydrate-electrolyte beverage, in comparison to drinking a prescribed volume of the same beverage or no drinking. [ABSTRACT FROM AUTHOR]