Parents often notice that some children seem able to stay focused and think carefully before acting, while others react quickly without stopping to think. A new study suggests that physical fitness and body fat may each influence these abilities in different ways.
Scientists from Northeastern University explored how children’s bodies and brains are connected. They focused on inhibitory control, which is the mental ability to pause, ignore distractions, and stop automatic actions when necessary. This skill is important for classroom learning, attention, and everyday decision-making.
The study involved around 100 children between 9 and 10 years old. Rather than using body weight alone, the researchers measured each child’s body composition with a DEXA scanner, which can accurately separate fat from muscle and other tissues.
The children also completed an exercise test on a treadmill. By measuring oxygen use during exercise, the researchers could determine each child’s aerobic fitness, which reflects how efficiently the heart, lungs, and muscles work together.
To measure self-control, the children completed a computer game involving friendly pictures of lions and tigers. After becoming used to pressing a button for one animal, they suddenly had to switch the rules, making it much harder to avoid pressing the button automatically.
Brain activity was recorded throughout the task using electroencephalography, or EEG. This allowed the researchers to study not only how well the children performed but also how their brains responded.
Children with better aerobic fitness were more accurate during the difficult parts of the task. Their brain recordings also suggested they devoted more mental resources to maintaining attention and controlling their responses.
Higher body fat was linked to a different result. These children tended to respond more impulsively during the task, although they were not less accurate overall. This suggests that body fat mainly influenced how quickly they reacted rather than how often they answered correctly.
Because the researchers measured body fat and fitness separately, they could show that each factor had its own independent relationship with brain function. This is important because two children with the same weight can have very different amounts of muscle and body fat.
The researchers believe these findings may help explain why regular exercise benefits children’s learning as well as their physical health. They also show that body composition and fitness should not be treated as the same thing in future research.
The study was published in Scientific Reports.
This study is strengthened by its use of advanced body scans, exercise testing, and direct brain measurements, making it one of the more detailed studies in this area. However, it does not prove that exercise alone causes better inhibitory control because other lifestyle factors may also contribute. Larger long-term studies and exercise interventions will be needed to confirm whether improving fitness leads to lasting improvements in children’s brain function and behavior.
Source: Northeastern University.
