by: S. L. Baker
Want to raise healthy and smart children? Then don’t allow them to be couch potatoes. Exercise, it turns out, does more than benefit the body and overall health — physical fitness builds smarter brains in youngsters, too.
That’s the news from a study just published in the journal Brain Research. Scientists used magnetic resonance imaging (MRI) to measure the relative size of specific structures in the brains of 49 children, all of whom were 9 or 10 years old. The research team discovered that the hippocampus (part of the brain inside the temporal lobe that plays an important part in memory and learning) tended to be significantly larger in the kids who were physically fit. What’s more, the fit children performed better on a memory test than youngsters the same age who were out of shape.
“This is the first study I know of that has used MRI measures to look at differences in brains between kids who are fit and kids who aren’t fit. Beyond that, it relates those measures of brain structure to cognition,” University of Illinois psychology professor and Beckman Institute director Art Kramer said in a statement to the media. Dr. Kramer headed the study along with doctoral student Laura Chaddock and kinesiology and community health professor Charles Hillman.
The researchers zeroed in on the hippocampus because it has long been known this brain structure is intricately involved in both learning and memory and that a larger hippocampus is associated with better performance on spatial reasoning and other cognitive tasks. Moreover, previous research in older adults and animals has shown that exercise can increase the size of the hippocampus.
For the new study, the University of Illinois scientists measured the children’s physical fitness levels by seeing how efficiently the youngsters used oxygen while running on a treadmill. “The physically fit children were much more efficient than the less-fit children at utilizing oxygen,” Dr. Kramer noted.
When the researchers analyzed the MRI data on the young research subjects, they found the fit kids tended to have significantly larger hippocampal volume. In fact, this part of the physical fit kids’ brains was a whopping 12 percent bigger, relative to total brain size, than the hippocampus in out-of-shape youngsters. What’s more, the children who were in better physical condition also scored higher on tests of relational memory (the ability to remember and integrate various types of information) than their less-fit peers.
“Higher fit children had higher performance on the relational memory task, higher fit children had larger hippocampal volumes, and in general, children with larger hippocampal volumes had better relational memory,” Dr. Chaddock concluded in the media statement.
“We knew that experience and environmental factors and socioeconomic status all impact brain development,” Dr. Kramer added. “If you get some lousy genes from your parents, you can’t really fix that, and it’s not easy to do something about your economic status. But here’s something that we can do something about.”
Bottom line: getting children out of the house and playing sports, biking or being physically active in other ways could have an important effect on brain development and even intelligence.
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