Effects of Caffeine Ingestion on Anaerobic Capacity in a Single Supramaximal Cycling Test

The aim of this study was to verify the effects of caffeine on anaerobic capacity estimated by the sum of the estimated glycolytic [E([La])] and phosphagen [E(PCr)] metabolism based on blood lactate and excess post-oxygen consumption responses (AC([La−]+EPOCfast)). Fourteen male cyclists were submitted to a graded exercise test to determine the maximal oxygen uptake ([Formula: see text]) and intensity associated with [Formula: see text] (i [Formula: see text]). Subsequently, the participants performed two supramaximal efforts at 115% of i [Formula: see text] to determine the AC([La−]+EPOCfast), after previous supplementation with caffeine (6 mg·kg(−1)) 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([La−]+EPOCfast) values from the placebo (4.06 ± 0.83 L and 55.2 ± 5.7 mL·kg(−1)) and caffeine condition (4.00 ± 0.76 L and 54.6 ± 5.4 mL·kg(−1)); however, a significant correlation was observed only for AC([La−]+EPOCfast) expressed in absolute values (r = 0.74; p < 0.002). The E([La]) and E(PCr) 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.