A new study suggests nine and 10-year-olds who are more aerobically fit have mire fibrous and compact white matter tracts in their brain than those who are less fit.
"White matter" is bundles of axons responsible for carrying nerve signals from one brain region to the other, the University of Illinois at Urbana-Champaign reported.
"Previous studies suggest that children with higher levels of aerobic fitness show greater brain volumes in gray-matter brain regions important for memory and learning," said University of Illinois postdoctoral researcher Laura Chaddock-Heyman.
To make their findings the researchers used diffusion tensor imaging (DTI) to look at five white-matter tracts in the brains of 24 participants. The technique looks at water diffusion into brain tissue, less water in the tissue means it is more fibrous and compact.
The analysis revealed significant differences in the integrity of white-matter tracts in fit and less fit children.
"All of these tracts have been found to play a role in attention and memory," Chaddock-Heyman said.
The research team is now two years into a five-year randomized, controlled trial that looks at whether or not the white-matter tract integrity improves in children who start a new fitness routine and maintain it over time.
"Prior work from our laboratories has demonstrated both short- and long-term differences in the relation of aerobic fitness to brain health and cognition. However, our current randomized, controlled trial should provide the most comprehensive assessment of this relationship to date," said kinesiology and community health professor Charles Hillman.
The findings add evidence that aerobic exercise changes the cognitive function of the brain.
"This study extends our previous work and suggests that white-matter structure may be one additional mechanism by which higher-fit children outperform their lower-fit peers on cognitive tasks and in the classroom," Chaddock-Heyman said.
The findings were published in the open-access journal Frontiers in Human Neuroscience.
