Forskning

August 15, 2011

he effect of adding caffeine to post exercise carbohydrate feeding on subsequent high-intensity interval-running capacity compared with carbohydrate alone

C Taylor et al, The effect of adding caffeine to post exercise carbohydrate feeding on subsequent high-intensity interval-running capacity compared with carbohydrate alone,International Journal of Sport Nutrition and Exercise Metabolism, 2011.

The aim of this study was to test the hypothesis that adding caffeine to post exercise carbohydrate feedings improves subsequent high-intensity interval-running capacity compared with carbohydrate alone. In a repeated measures design, 6 men performed a glycogen-depleting exercise protocol until volitional exhaustion in the morning. Immediately after and at 1,2, and 3 hours post exercise, participants consumed 1.2 g/kg body mass carbohydrate of a 15% carbohydrate solution, a similar carbohydrate solution but with the addition of 8 mg/kg body mass of caffeine, or an equivalent volume of flavoured water only.  After the 4 hour recovery period, participants performed the Loughborough Intermittent Shuttle Test (LIST) to volitional exhaustion as a measure of high-intensity interval-running capacity. Average blood glucose levels during the 4-hr recovery period were higher in the carbohydrate conditions than in the flavoured water only trial, although there was no difference between carbohydrate and carbohydrate and caffeine. Exercise capacity during the LIST was significantly longer in the carbohydrate and caffeine trial than in the carbohydrate and water only conditions. All 6 participants improved performance in the carbohydrate caffeine compared with carbohydrate. ‘The study provides novel data by demonstrating that adding caffeine to post exercise carbohydrate feeding improves subsequent high-intensity interval-running capacity, a finding that may be related to higher rates of post exercise muscle glycogen resynthesis previously observed under similar feeding conditions’.