Children who are fitter have more brain power, according to new research.
A study of eight to 11-year-olds found exercise boosted grey matter in nine different areas.
These were important for cognition, executive function and academic achievement, say scientists.
It is the first time the dramatic effect of physical activity on the structure of the brain has been identified.
The Spanish team believe it will have an influence on their performance in exams and, consequently, future career success.
A third of children in the UK are overweight or obese with a fifth afflicted even before they begin primary school.
A Spanish study of eight to 11-year-olds found exercise boosted grey matter in nine different areas (stock image)
Dr Francisco Ortega, of the University of Granada’s Sport and Health Institute in Spain, said the findings add to evidence exercise protects older people against Alzheimer’s disease.
Key findings
His researchers found the children’s physical fitness, especially aerobic and motor ability, was directly linked to more neurons in specific areas of the brain known as the cortical and subcortical regions.
Aerobic fitness is the capacity to do exercise for a long time and efficiently.
In particular, this was associated with more grey matter in the premotor cortex, which is important for learning (imitation) and social cognition (empathy) as well as controlling movements.
This type of exercise also boosts the power of the the parahippocampal gyrus and hippocampus which controls memory.
It also affects the inferior temporal gyrus, which plays a role in remembering to recognize visual stimuli and the caudate nucleus which is involved in learning.
The study, published in Neuroimage was part of the ActiveBrains project and involved more than 101 overweight and obese children.
Dr Ortega said: ‘Our work aims at answering questions such as whether the brain of children with better physical fitness is different from that of children with worse physical fitness and if this affects their academic performance.
‘The answer is short and forceful: yes, physical fitness in children is linked in a direct way to important brain structure differences, and such differences are reflected in the children’s academic performance.’
‘To the best of our knowledge, no previous study has examined the association of physical fitness with gray matter volume in overweight or obese children using whole brain analyses.’
Improved academic performance
Importantly, he said the research found motor ability helped fuel grey matter in two regions essential for language processing and reading – the inferior frontal gyrus and the superior temporal gyrus.
Interestingly, there was no link between muscular strength and better function in any area of the brain.
Main author Dr Irene Esteban-Cornejo said grey matter volume in the cortical and subcortical regions influenced by physical fitness improved the children’s academic performance.
Moreover, she added: ‘Physical fitness is a factor that can be modified through exercise, and combining exercises that improve the aerobic capacity and the motor ability would be an effective approach to stimulate brain development and academic performance in overweight or obese children.’
The group found the children with higher aerobic fitness have more neurons in ‘nine cortical and subcortical brain regions relevant for cognition, executive function and academic achievement’.
The researchers called for their findings to be taken into account by educational and public health institutions.
Exercise reduces dementia risk in adults
Exercise has long been known to improve brain health by boosting blood flow to grey matter. One hour a day has even been found to halve the risk of Alzheimer’s disease.
Dr Ortega said: ‘Differences in brain volumes according to physical fitness are not only observed in the growing brains of children, but also in adults and in older adults in which brain volume is known to shrink as a person ages.
‘Several investigations have consistently shown that hippocampus volume is larger in fitter older adults than in their less fit peers.’
He referred to the results of another study which showed that one year of aerobic training in older adults did not only reduce the natural decline in the hippocampus, but even reversed increasing its volume by 2 percent and leading to improvements in memory function.
‘Collectively, existent evidence concisely supports that individuals with a better aerobic fitness level, have more developed certain regions of the brain, which in turn has shown to positively influence cognition.
‘Therefore, there is emerging evidence suggesting that to exercise and be in a good fitness level is healthy not only for the body, but also for the brain and cognition.’
He said the message is: ‘Be smart, exercise your heart.’