Brain uses lactate, not glucose, during exercise

Researchers in Denmark and The Netherlands have discovered that during exercise, the human brain shifts into a higher gear and uses an "alternative energy" source: it does not feed on glucose but on lactate.

Johannes J. Van Lieshout of the University of Amsterdam, and colleagues found that, like our muscles, the brain works harder during strenuous exercise and shifts from glucose metabolism to lactate metabolism. This may help to explain why the brain continues to work well during times of high demand for oxygen and fuel throughout the body.

Not only does the brain change its metabolism during strenuous exercise, according to this study, but it also changes into a higher gear of activity. Now researchers will be focusing on what the effect of lactate is on the brain.