High-intensity interval exercise (HIIE) improves cerebral executive function (EF), but the improvement in EF is attenuated after repeated HIIE, perhaps because of lower lactate availability for the brain. This investigation examined whether improved EF after exercise relates to brain lactate uptake. Fourteen healthy, male subjects performed 2HIIEprotocols separatedby 60min of rest.Blood sampleswere obtained fromthe right internal jugular venous bulb and from the brachial artery to determine arterial-venous differences across the brain for lactate (a-v diff_lactate), glucose (a-v diff_glucose), oxygen (a-v diff_oxygen), and brain-derived neurotrophic factor (BDNF; a-v diffBDNF). EF was evaluated by the color-word Stroop task. The first HIIE improved EF for 40 min, whereas the second HIIE improved EF only immediately after exercise. The a-v diff_glucose was unchanged, whereas the a-v diffBDNF increased similarly after both HIIEs, and the a-v diff_lactate increased, but the increase was attenuated after the secondHIIE, compared with the firstHIIE (P < 0.05).The EF after HIIE correlatedwith the a-v difflactate (r²=0.62; P < 0.01). We propose that attenuated improvement in EF after repeated HIIE relates to reduced cerebral lactate metabolism and is, thereby, linked to systemic metabolism as an example of the lactate shuttle mechanism.