Exercise is a brain drug. Here’s the biology behind it New review in Frontiers in Molecular Neuroscience breaks down how exercise boosts brain BDNF, the key molecule for learning and memory. What matters most: 1. Exercise reliably increases brain BDNF, a driver of neuroplasticity and neurogenesis 2. BDNF supports memory, learning, mood, and stress resilience 3. Blocking BDNF signaling removes many cognitive benefits of exercise How exercise raises BDNF: 4) Neuronal activity increases calcium signaling and gene expression 5) Increased cerebral blood flow activates endothelial BDNF production 6) Muscle and liver release exerkines like lactate, irisin, IGF-1, and ketones that signal the brain 7) Brain BDNF comes from neurons, blood vessels, and peripheral organs working together Exercise isn’t just movement, it’s a whole body signal that rewires the brain from the inside out.