John Ratey quotes:

If you had half an hour of exercise this morning, you're in the right frame of mind to sit still and focus on this paragraph, and your brain is far more equipped to remember it.

Even 10 minutes of activity changes your brain.

Exercise is really for the brain, not the body. It affects mood, vitality, alertness, and feelings of well-being.

Exercise is the single best thing you can do for your brain in terms of mood, memory, and learning.

Exercise is the single most powerful tool you have to optimize your brain function"¦exercise has a profound impact on cognitive abilities and mental health. It is simply one of the best treatments we have for most psychiatric problems.

It turns out that moving our muscles produces proteins that travel through the bloodstream and into the brain, where they play pivotal roles in the mechanisms of our highest thought processes.

At every level, from the microcellular to the psychological, exercise not only wards off the ill effects of chronic stress; it can also reverse them. Studies show that if researchers exercise rats that have been chronically stressed, that activity makes the hippocampus grow back to its preshriveled state. The mechanisms by which exercise changes how we think and feel are so much more effective than donuts, medicines, and wine. When you say you feel less stressed out after you go for a swim, or even a fast walk, you are.

We can know ourselves only because we can remember.