Aerobically Fit Children have more Compact White Brain Matter than Less-Fit Children
Exercise is not only good for the body, it is also good for the brain. In a new study, researchers examined the effects of exercising on the brains of young children. They discovered that children who are aerobically fit have more compact white matter in their brains than children who are less active.
"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 reported in the press release. "Now for the first time we explored how aerobic fitness relates to white matter in children's brains."
White matter consists of the bundles of axons that are responsible for carrying nerve signals from one part of the brain to another. Based on previous research, more compact white matter has been linked to faster and more efficient brain activity.
For this study, Chaddock-Heymon worked with kinesiology and community health professor Charles Hillman and psychology professor and Beckman Institute director Arthur Kramer. They recruited 24 children between the ages of nine and 10 and used diffusion tensor imaging (DTI) in order to analyze five white-matter tracts in the brain. DTI works by examining water diffusion in tissues. Less water diffusion indicates more fibrous and compact white matter. The researchers controlled factors such as social and economic status, puberty time, intelligence quotient (IQ) and neurodevelopmental disorders.
The researchers found differences in the integrity of three white-matter tracts between children who were physical fit and children who were not. The tracts were the corpus callosum, the superior longitudinal fasciculus and the superior corona radiata. These tracts have been linked to attention and memory. However, the team did not test and compare the children's cognitive functions.
"Previous studies in our lab have reported a relationship between fitness and white-matter integrity in older adults," Kramer said. "Therefore, it appears that fitness may have beneficial effects on white matter throughout the lifespan."
Chaddock-Heyman added, "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."
The research team is currently two years into a five-year randomized, controlled trial that will determine whether or not white matter tract integrity will improve in children who start and maintain a long-term physical fitness routine. The study, "Aerobic fitness is associated with greater white matter integrity in children," was published in the journal, Frontiers in Human Neuroscience.