Physical fitness especially cardiorespiratory fitness, speed-agility and muscular fitness, leads to the presence of more grey matter in the brain.
Increase in grey matter in various regions of the brain boosts learning, functioning and reading processes of the child, the researchers said, in the paper published in the journal Neuroimage.
"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," said Francisco B. Ortega, researcher at the University of Grenada in Spain.
"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," Ortega added.
The researchers assessed academic performances of 101 obese children, aged between eight to 11 years, in accordance with the volume of grey matter present in the brain.
The results showed that higher cardiorespiratory fitness was related to greater grey volumes, specifically in frontal regions, subcortical regions, temporal regions and the calcarine cortex region of the brain.
However, muscular fitness was not independently associated with greater grey matter volume in any brain region.
"Physical fitness is a factor that can be modified through physical 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/obese children," the researchers noted.