From the Mayo Clinic…
Research has long shown that exercise can improve brainpower and hold off age-related memory loss. New studies show that adding strength training to your normal exercise routine may improve your memory by stimulating a hormone that protects brain cells. It’s easy! Lift hand weights, use resistance tubing, or do squats or push-ups. [...]

This just in from Science Daily…socializing appears to be good for your intelligence!
Humans are social animals; we spend much of our time with others in groups. We are also wise. It is not our size, speed, or strength that distinguishes us from other mammals, but our intelligence. How might these two features — being social [...]