Exercise is known to ultimately boost the release of brain-derived neurotrophic factor (BDNF), a hormone essential for brain health. One trigger for the underlying cascade is thought to be increasing lactate in the blood, produced by skeletal muscle through the oxygen-poor metabolism that is typical of high-intensity exercise. Now, sports scientists have shown for the first time that an IV infusion with lactate is sufficient to stimulate the release of the biologically active precursor molecule pro-BDNF. So while this might be enough to trigger the release of a brain-boosting hormone without exercising, researchers warn it’s not an excuse not to make that morning run.