The old saying healthy body, healthy mind has been proved true in physically fit children.
U.S. researchers have shown for the first time that youngsters who are more aerobically fit have more ‘white matter’ in their brains, which is a marker for better memory and attention.
A new study used brain imaging to explore the link between body and mental fitness in nine and 10-year-olds.
Those rated at a higher level of fitness also had brains with more fibrous and compact white matter, the network of nerve fibres important for sending signals between different brain regions.
Joint study author Laura Chaddock-Heyman, of Illinois University, said: ‘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.
‘Now for the first time we explored how aerobic fitness relates to white matter in children’s brains.’
She said the study found significant fitness-related differences in the strength of several white matter tracts in the brain connecting different regions.
Dr Chaddock-Heyman said: ‘All of these tracts have been found to play a role in attention and memory.’
It 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,’ she added.
Although the study did not test for cognitive differences in children with different fitness levels, previous research has found fit adults perform better on white matter-related tasks.
Psychology professor Doctor Arthur Kramer said: ‘Previous studies in our lab have reported a relationship between fitness and white-matter integrity in older adults.
‘Therefore, it appears that fitness may have beneficial effects on white matter throughout the lifespan.’
The researchers looked at 24 children given scans using diffusion tensor imaging (DTI, also called diffusion MRI) to investigate five white matter tracts.
White matter describes the bundles of nerve fibres carrying signals from one brain region to another, with more compact white matter linked with faster and more efficient nerve activity.
The scans analyse water diffusion into tissues, with less water diffusion denoting more fibrous and compact material with ‘desirable traits’, says a report in the journal Frontiers in Human Neuroscience.
Researchers took into account factors such as social and economic status, the timing of puberty, IQ, or a diagnosis of ADHD or other learning disabilities that might have affected the reported fitness differences in the brain.
The analysis revealed significant fitness-related differences in the integrity of several white-matter tracts in the brain.
To take the findings further, the team is now two years into a five-year trial to determine whether white-matter tract integrity improves in children who begin a new physical fitness routine and maintain it over time.
C-researcher Professor Charles Hillman said: ‘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 trial should provide the most comprehensive assessment of this relationship to date.’