Children aged between 4 and 6 who have better cardiorespiratory health than their peers also do better on cognitive tests and other measures of brain function.

The finding comes from a study, by researchers at the University of Illinois Urbana-Champaign (UIUC), which suggests that the link between cardiorespiratory fitness and cognitive health is evident even earlier in life than previously appreciated.

Most studies of the link between fitness and brain health focus on adults or preadolescent or adolescent children. Research has also consistently found positive correlations between people’s aerobic exercise capacity and their academic achievement and cognitive abilities.

UIUC's Shelby Keye, who led the research, said: "Studies have found that higher cardiorespiratory fitness in older children and adults corresponds to the relative size and connectivity of brain structures that are important to cognitive control.

“But it isn’t yet known at what point in the developmental trajectory of childhood this relationship emerges."

To better understand the relationship between cardiorespiratory fitness and brain health in 59 preschool-aged children, the researchers subjected them to several tests.

The children walked as far as they could in six minutes, a test that allowed researchers to estimate their cardiorespiratory fitness.

An early cognitive and academic development test gave the team a measure of each child’s intellectual abilities, and a computerised “flanker” task measured how well they were able to focus on the important part of an image while ignoring distracting information.

Participants also took part in a computerised task that required them to alter their responses depending on whether flowers or hearts appeared on the screen – a measure of mental flexibility.

Statistical analyses revealed a relationship between the children’s physical fitness and their cognitive abilities and brain function, the researchers said.

“Preschool children with higher estimated cardiorespiratory fitness had higher scores on academic ability tasks related to general intellectual abilities as well as their use of expressive language,” Keye said.

“They had better performance on computerizsd tasks requiring attention and multitasking skills, and they showed the potential for faster processing speeds and greater resource allocation in the brain when completing these computerised tasks.”

• To study was published in the Journal of Clinical Medicine. To read the full article, click here.