There's a very convincing and well researched book on this issue: Spark! How exercise will improve the performance of your brain. The gist: aerobic exercise he

There's a very convincing and well researched book on this issue: Spark! How exercise will improve the performance of your brain. The gist: aerobic exercise helps neurogenesis and connectivity in the brain. Running is best if i remember correctly, or maybe that was just my private conclusion.