Aerobic exercise causes a steep spike in blood movement to the brain, an action that some researchers have speculated might be necessary for the creation of new brain cells, or neurogenesis. Running and other forms of aerobic exercise have been shown, in mice and men, to lead to neurogenesis in those portions of the brain associated with memory and thinking, providing another compelling reason to get out at lunchtime and run.
...Since weight training doesn’t cause the same spike, few researchers have thought that it would have a similar effect. But recent studies intimate otherwise. Several studies involve animals. It’s not easy, of course, to induce a mouse or a lab rat to lift weights, so the experimenters have to develop clever approximations of resistance training to see what impact adding muscle and strength has on an animal’s brain.
And one result has been smarter, stronger, muscled-up rats. Great - I am putting my cats on a weight program ASAP.