Willian E Miyagi, Romulo C Bertuzzi, Fabio Y Nakamura, Rodrigo A B de Poli, Alessandro M Zagatto
The aim of this study was to verify the effects of caffeine on anaerobic capacity estimated by the sum of the estimated glycolytic [E] and phosphagen [E] metabolism based on blood lactate and excess post-oxygen consumption responses (AC). Fourteen male cyclists were submitted to a graded exercise test to determine the maximal oxygen uptake ( ) and intensity associated with (i ). Subsequently, the participants performed two supramaximal efforts at 115% of i to determine the AC, after previous supplementation with caffeine (6 mg·kg) or a placebo (dextrose), in a cross over, randomized, double blind, and placebo-controlled design. The time to exhaustion was higher in the caffeine (186.6 ± 29.8 s) than in the placebo condition (173.3 ± 25.3 s) (p = 0.006) and a significant correlation was found between them (r = 0.86; P = 0.00008). Significant differences were not found between AC values from the placebo (4.06 ± 0.83 L and 55.2 ± 5.7 mL·kg) and caffeine condition (4.00 ± 0.76 L and 54.6 ± 5.4 mL·kg); however, a significant correlation was observed only for AC expressed in absolute values (r = 0.74; p < 0.002). The E and E also presented no significant differences and they were significantly correlated (r = 0.82 and r = 0.55, respectively; p < 0.05). We conclude based on the overall comparison of mean values between two treatments that acute caffeine ingestion improves the time to exhaustion but does not affect anaerobic capacity estimation.
