Here are some interesting thoughts from Dr. John Ratey, associate professor of psychiatry at Harvard, and author of, Spark: The Revolutionary New Science of Exercise and the Brain:

“We all know that exercise makes us feel better, but most of us have no idea why.  We assume it’s because we’re burning off stress or reducing muscle tension or boosting endorphins, and we leave it at that.

But the real reason we feel so good when we get our blood pumping is that it makes the brain function at its best, and in my view, this benefit of physical activity is far more important—and fascinating—than what it does for the body.

Building muscles and conditioning the heart and lungs are essentially side effects. I often tell my patients that the point of exercise is to build and condition the brain.” (my emphasis)

The key takeaway for Kaizen (improvement-minded) Swimmers?

Brain cells born from swimming are different from those created by running.  And far more (and more useful) brain cells are created by swimming that is focused intently on improving skill than by swimming that’s focused on “getting through” a workout or “getting in” a certain number of yards.

A brain neuron