Physical activity and exercise, such as aerobic, thin out the gray matter in the children aged between 9 and 10, claims a new study. According to a team of researchers at the University of Illinois, the thin gray matter or the layer of brain cells in the cerebrum is associated with better mathematical skills.

The study suggests that cardiorespiratory fitness in children leads to thinning of the gray matter, a process which is part of the normal brain development in children. The study further provides an evidence that physical fitness contributed to the development of brain structures responsible for mathematical achievement, enhancing the maths skills and ability in an individual.

According to the lead researcher Laura Chaddock-Heyman, the thinning of the gray matter is part of the natural sculpting of the healthy, fully formed brain. Heyman further confirmed that the study has found that 9- and 10-year-olds, who are fitter than their counterparts, tend to show a decrease in gray-matter thickness in some parts of the frame that develop over a period of time.

During the study, the researchers divided a group of 48 children, who passed a treadmill test in two subgroups. The first subgroup scored over 70th percentile in terms of aerobic fitness, while the second subgroup of children had scored below 70. The research team then analyzed the brains of the children using MRI and also asked them to complete an analytical test which assessed their spelling, math and reading skills.

The researchers noticed a difference in the cortical structure of the high-fit and low-fit children, and discovered that those who had the thinner gray matter scored greater in mathematics assessment.

"Given that rates of physical inactivity are rising, there is an increased need to promote physical activity. Schools are the best institutions to implement such health behavior practices, due to the number of children they reach on a daily basis," the researchers concluded.