e means half the risk of dementia and half the risk of cognitive impairment for these older adults. In this time of increased longevity, regular exercise is an important protective element against the progression of age, if we hope to live not just longer, but better.

Two more reasons why exercise improves cognition are the following: First, exercise increases oxygen flow to the brain, which reduces brain-bound free radicals. In addition, in order to get more oxygen to the brain, you need more blood vessels, and exercise increases and deepens blood vessels. And second, exercise acts directly on the molecular machinery of the brain itself; it increases neurons’ creation, survival, and resistance to damage and stress.

How Exercise Promotes Learning In “Spark: The Revolutionary New Science of Exercise and the Brain”, Dr. John Ratey, clinical associate professor of psychiatry at Harvard Medical School, contends that “exercise is the single most powerful tool you have to optimize brain function.”  In his book, he explains how sustained aerobic exercise promotes learning in three main ways. First,exercise activates the executive functioning area of the brain, or the frontal cortex.  This activation makes people more attentive, less impulsive, and less fidgety.  When someone can sustain their attention for a longer period of time, it promotes their ability to sort though information and better absorb it. Dr. Ratey explains that the second way in which exercise improves the functioning of the brain is that it improves the environment in which the nerve cells in our brains live.  It does this by promoting the release of neurotransmitters, hormones, and other elements of brain chemistry which help prime these cells to perform their functions efficiently.

Third, exercise promotes neurogenesis, or the process of growing new brain cells. Although for many years it was believed that the number of neurons  in the adult brain remained fixed, research conducted in the last few years has shown otherwise.  Specifically, exercise adds more brain cells in the area of the brain which has to do with learning and memory, which is an areacalled the hippocampus, also known as “The Grand Central Station” for memory. In fact, Dr. Ratey goes on to say that there’s nothing that we know of that adds new brain cells better than exercise.

So, for how long should you exercise? Dr. Ratey recommends that you exercise about thirty minutes a day, almost daily.

As an aside, teachers and parents will want to read about the revolutionary fitness program in Naperville, Illinois–documented in“Spark”–which put the local school district of 19,000 kids first in the world in science test scores. Conclusion As Dr. Medina points out, exercise strengthens muscles and bones, reduces the risk of Alzheimer’s, regulates appetite, im

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