The accumulation of lactate in the blood after a high-intensity exercise is associated to an increase of lactate extractions by the brain. However, no information has been provided about the influences of blood lactate on cognitive performances and, in particular, on attention. The present study was carried out to examine the association of high blood lactate levels, induced with a maximal cycling, with two different attentional tasks. The study was carried out on 17 male sprinters who performed exhaustive exercise. Before the exercise, as well as 5 and 10 min after the exhaustion, blood lactate was measured and intensity as well as selectivity of attention of each subject were evaluated. Same measurements were performed on 6 out of 17 subjects who accepted to receive an intravenous infusion of a lactate solution. In both experimental conditions, an inverse relation between scores in both aspects of attention and blood lactate levels was observed.