A couple of days ago I mentioned the book Spark that I had ordered, having read about it from Frank Forencich . Bill De Simone commented on the post and summarised the argument: the gist of his book is that running, swimming, etc. benefits creativity, concentration, mood, other brain aspects, more so than weight training and stretching, due to the increased blood flow to the brain. He doesn't devalue weight training/yoga/stretching, just draws a distinction between benefits. Increased heart rate alone, such as from blood pooling during weight training, isn't enough; there has to be the steady increased flow. I just saw this study reported which seems to support that position: In the first study to demonstrate a clear positive association between adolescent fitness and adult cognitive performance, Nancy Pedersen of the University of Southern California and colleagues in Sweden find that better cardiovascular health among teenage boys correlates to higher scores on a range of ...