Exercise and our brains
By Liz Montes
At the 2012 annual meeting of the Society for Neuroscience, one of their most interesting studies again documented the overwhelming amount of evidence of how exercise strengthens the “structure and function of the brain.”
There is evidence in both animal and human studies of how exercise after a just few months improves brain neurons, lifts moods and bolsters memory and thinking. Most interesting was that the studies went on to discuss what happens to the brain when we stop exercising. Does it revert to its old self? Or, are the improvements permanent to the brain?
I found this especially interesting because we have noticed in the gym, of course totally unscientific, that we do see some simple differences. The person who’s been away for a longer period of time not only takes more time to return to higher fitness levels but also seems to take more time to remember how to execute the exercise than the folks who train most consistently. Does this carry over to life outside the gym? Perhaps it does.
At the University of Sao Paulo scientists injected into adult rats a substance that marks newborn neurons in the hippocampus of the brain (the memory center). This would help them monitor how many new neuron cells were being created. Inactive rats and people always create new brain cells, however, the active create two to three times more new hippocampus neurons.
A separate group of inactive rats were also monitored for brain cell activity.
After one week, both active and sedentary rats were introduced to a platform that allowed them to swim, which apparently rats love to do, and taught them how to find and remember where the platform was that allowed them to swim. Those with the best memories swam to the platform fastest.
After one week of inactivity they found that the rats which were able to find the platforms fastest had more brain activity and neurons. The rats that had been inactive for three weeks had far fewer brain neurons and activity than the one-week sedentary rats, and the inactive six-week rats had even less.
The conclusion was that the rats who had been inactive three to six weeks performed far worse on the swimming memory test than the rats who had not exercised for only one week.
A senior author of the study Dr. Michael Mazurek, a professor of neurology, who oversaw the study, stated, “this is analogous to muscle bulk or heart rate following exercise withdrawal.” Gilberto Xavier. another professor overseeing the study, agreed. “Brain changes are not maintained when physical activity is interrupted.” Adding that, although the study was restricted to rats, indirect evidence suggests the phenomenon occurs in human beings as well.
There have been many studies that point in the same direction. For the ongoing health of our minds as well as our bodies, exercise is an extraordinary boost.
Even anthropologists have been intrigued by human physical endurance shaping our brains. The journal Nature posted an article titled “Endurance Running and Evolution of Homo.”
The article suggests that our ancestors actually survived by becoming endurance athletes, able to bring down faster, larger prey by sheer determination and will, jogging and plodding behind them until they fell. Endurance produced meals which in turn produced the strongest, fastest, smartest humans to pass on their genes. The developing rapidly brain— indicated that it was movement that shaped and developed not only the human body but the brain too.
Today, anthropologists believe that humans have a brain that is three times the size that would be expected, given our body size in comparison to the body size of other mammals. The broad point being that being in motion makes us smarter.
Whatever the truth, most people will tell you that they feel, function and look better when they are exercising.
Liz Montes is a fitness trainer