Exercise can stimulate the creation of new brain cells – at least in rats.
After running, the number of neurons in the hippocampus doubled and even tripled in some rats. High-intensity interval training (HIIT) also stimulated neurogenesis, but not nearly as much as running. Finally, weight-training had no effect on brain cell creation.
Obviously, rats are not people. HIIT and weight-training are valuable exercises, but are often more stressful than running and stress can reduce neurogenesis. Although running may increase brain cells, other exercises may provide other brain-health benefits like new blood vessels and neuronal connections.
Whatever exercise you do, don’t forget to sneak a little aerobics in there somehow.
NYTimes article: Which exercise is best for the brain?
Study: Physical exercise promotes neurogenesis