An excellent blog post at the NY Times, by writer Gretchen Reynolds, on how exercise impacts the brain. No matter you are young, middle-aged, or old, male or female, these effects are powerful, and if you can find a way to train consistently, long-lasting. Look at this way, even if scientists are off by a factor of 50% in the estimated beneficial impact on the brain, just a few hours per week of vigorous movement can give your life a huge. So little to do to feel better, look better, and be more productive every day.

My dad suffered from bipolar depression — severe and unrelenting — for over 30 years, long before advent of drugs like Prozac and other compounds to treat depression. Exercise was his treatment. He took three walks every day, played tennis when possible, and swam in the warm months. Did it cure him? Of course not. But, it helped him live and was one of the few anchors to normalcy that he (and our family) had in life. Never underestimate the power of exercise.

Fortunately, I did not inherit my father’s mental illness, but I did get from him a devotion to physical training. I started lifting in 1975 and have not stopped for 42 years. Along the way, I have also been a runner and cyclist, and I am now pursuing my Black Belt in Shotokan karate at the Missouri Karate Association. For me, exercise is inseparable from living a good life, and, intellectually, I feel as capable and resilient as I have ever been. That’s no accident.

“It’s incredible just how pervasive and complex the effects of exercise are on the brain,” said Moses Chao, a professor at the Skirball Institute of Biomolecular Medicine at N.Y.U. who oversaw the study.

Whether the same mechanisms that occur in mice occur in our own brains when we exercise is still unknown. But, Dr. Chao pointed out, like the mice, we have more B.D.N.F. in our bodies after exercise. We also create ketones when we exercise, and those ketones are known to migrate to our brains..

Generally, however, this process requires exerting yourself vigorously for an hour or more, after which time your body, having exhausted its stores of sugar, starts burning stored fat and making ketones.

Well | How Exercise May Help the Brain Grow Stronger