Children who are fitter tend to have better-developed brains than out-of-shape ones. Researchers from the University of Illinois studied 49 children aged nine to ten. They measured their fitness on a treadmill, used an MRI scanner to measure the volume of their hippocampus and tested their memory. The fitter children tended to have a bigger hippocampus - an area of the brain associated with learning and memory - about 12% larger than the unfit ones. The fitter children also did better on tests of relational memory - the ability to remember and integrate various types of information - but only if their hippocampus was bigger, suggesting that the link between fitness and a larger hippocampus was the crucial one.
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