Log 40 Hard Minutes of Cardio A Week
As we exercise, neurons from key brain areas, the hippocampus and cortex, secrete a memory-making hormone called brain-derived neurotrophic factor (BDNF) that helps increase the number of neurons we have and makes their synapses run more efficiently. It’s an evolutionary gift — or curse — from the days humans ran to hunt or avoid being eaten themselves, says Howard Fillet, MD, chief science officer of the Alzheimer’s Drug Discovery Foundation, adding, “If a lion starts chasing you from behind a tree and you escape, you’ll want to remember that event for the rest of your life.”
The harder and longer you work, the more BDNF flows to your bloodstream. A recent study points to a guaranteed BDNF bump from 40 vigorous minutes of cardio versus a more modest rise for 20 minutes at a moderate rate, says Matthew Schmolesky, PhD, who put humans through their paces at Weber State University in Utah to test BDNF levels.
Exercise also helps with weight control, a key point as fat literally goes to your brain. A recent review of studies says obesity in midlife, defined as a BMI of 30 or over, almost doubles your chances of getting dementia. Abdominal fat is particularly harmful; bigger guts have been linked to smaller brain volume. “Fat tissue, particularly the fat around the abdomen, releases chemicals called cytokines that can cause inflammation and are toxic to neurons in the brain,” Fillet says.Back to top