Maintained exercise-enhanced brain executive function related to cerebral lactate metabolism in men.
Level 3 - non-randomized controlled study
Single-arm within-subject repeated-measures physiological trial without a randomized control group.
PubMed 29127193 · doi:10.1096/fj.201700381RR
What was done
Fourteen healthy male participants completed two high-intensity interval exercise (HIIE) sessions separated by a 60-minute rest period. Executive function was evaluated using the color-word Stroop task. To determine cerebral metabolism, blood samples were collected from the brachial artery and the right internal jugular venous bulb to calculate arterio-venous differences for lactate, glucose, oxygen, and brain-derived neurotrophic factor (BDNF).
What was found
Executive function improved for 40 minutes after the first HIIE, but only immediately after the second HIIE. Arterio-venous difference for glucose was unchanged, while the arterio-venous difference for BDNF increased similarly after both bouts. Arterio-venous difference for lactate increased after both sessions, but the increase was attenuated after the second HIIE compared with the first (P < 0.05). Post-exercise executive function correlated with the cerebral arterio-venous difference for lactate (r2 = 0.62; P < 0.01).
Why it matters
This study provides direct invasive metabolic evidence in humans linking systemic exercise-induced lactate uptake across the brain to the maintenance of enhanced executive function.
Limits
The study had a small sample size (n = 14) and included only healthy men. There was no non-exercise control group or randomized crossover design to control for fatigue or task-learning effects. Correlation between lactate uptake and cognitive scores does not prove direct causality.
Cited by
- supports Post-exercise improvements in executive function in humans correlate directly with blood lactate levels rather than glucose levels.