Maintained exercise-enhanced brain executive function related to cerebral lactate metabolism in men.

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 2 HIIE protocols separated by 60 min of rest. Blood samples were obtained from the right internal jugular venous bulb and from the brachial artery to determine arterial-venous differences across the brain for lactate (a-v difflactate), glucose (a-v diffglucose), oxygen (a-v diffoxygen), 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 diffglucose was unchanged, whereas the a-v diffBDNF increased similarly after both HIIEs, and the a-v difflactate increased, but the increase was attenuated after the second HIIE, compared with the first HIIE ( P < 0.05). The EF after HIIE correlated with 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.-Hashimoto, T., Tsukamoto, H., Takenaka, S., Olesen, N. D., Petersen, L. G., Sørensen, H., Nielsen, H. B., Secher, N. H., Ogoh, S. Maintained exercise-enhanced brain executive function related to cerebral lactate metabolism in men.