Children who are physically active actually boost their own brain development, according to a study by the University of Illinois.
The researchers observed 49 participants, aged nine to ten, and found that physically fit children tend to have a bigger hippocampus and also perform better on memory tests than kids who are less fit.
For the study, magnetic resonance imaging (MRI) was used to measure the relative size of specific structures in the brains of the child participants.
“This is the first study I know of that has used MRI measures to look at differences in brain between kids who are fit and kids who aren’t fit. Beyond that, it relates those measures of brain structure to cognition,” said University of Illinois psychology professor Art Kramer, who led the study with Laura Chaddok, doctoral student.
The study’s main focus was the hippocampus, a structure set deep in the brain and known to play a major role in memory and learning. Previous studies in older adults and animals have shown that exercise can enlarge the hippocampus. A bigger hippocampus is linked to stronger spatial reasoning and other cognitive tasks.
“In animal studies, exercise has been shown to specifically affect the hippocampus, significantly increasing the growth of new neurons and cell survival, enhancing memory and learning, and increasing molecules that are involved in the plasticity of the brain,” said Chaddock.
To measure the participants’ physical fitness, researchers analyzed how efficiently the participants used oxygen while running on a treadmill.
“This is the gold standard measure of fitness,” Chaddock said.
According to Kramer, the physically fit children were “much more efficient than the less-fit children at utilizing oxygen.”
According to the MRI data, the children considered the most physically fit–those who best utilized oxygen–tended to have larger hippocampal volume than the less fit children. In fact, it was about 12 percent bigger, relative to total brain size.
Even further, the children who were in better shape had stronger relational memory skills– the ability to recall and assimilate different 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,” Chaddock said.
Further analyses proved that a bigger hippocampus was responsible for the enhanced performance on the relational memory task.
“If you remove hippocampal volume from the equation,” Chaddock said, “the relationship between fitness and memory decreases.”
The study suggests that taking steps to increase childhood physical activity could have a significant effect on brain development, Kramer said.
“We knew that experience and environmental factors and socioeconomic status all impact brain development,” he said.
“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,” Kramer said.
This study appears in the journal Brain Research.
Source: University of Illinois