Poor motor function in childhood may lead to lower academic achievement in adolescence, researchers reported.
In a large cohort of Finnish children, compromised motor function at age 8 was linked to poor academic outcomes at age 16 through both obesity and physical inactivity, according to Marko Kantomaa, PhD, of the Research Center for Sport and Health Sciences in Jyväskylä, Finland, and colleagues.
On the other hand, cardiorespiratory fitness did not appear to play a role, Kantomaa and colleagues reported online in the Proceedings of the National Academy of Sciences.
Aside from the well-known physical health risks of inactivity, increasing evidence suggests detrimental effects on young people's cognitive function and academic achievement, , the researchers noted.
They added that obesity has been shown to predict poor academic achievement and cognitive function in childhood.
Because childhood motor function is linked to cognitive development and growth, they hypothesized, it might play a role in later academic performance.
To investigate the issue, they turned to the Northern Finland Birth Cohort 1986, which was initially composed of 9,432 infants born between July 1, 1985, and June 30, 1986, in Oulu and Lapland, the two most northern provinces of Finland.
Data was collected during the mothers' pregnancies and follow-up surveys took place when the children were ages 7 or 8 and again when they were ages 15 or 16. For this study, the researchers referred to those surveys as taking place when the children were 8 or 16.
They analyzed data for 8,061 children (4,126 boys and 3,935 girls) who had complete information on academic achievement in the second survey.
Motor function was assessed in the first survey by asking parents how well their children handled some common childhood activities, such as catching a ball, and whether they often bumped into things or fell over.
Teachers rated their academic performance.
In the second survey, the teens were asked to evaluate their own physical activity outside of school and, if they commuted to school on foot, how long it took. The answers were converted into mean metabolic equivalent of task (MET) hours per week.
The researchers measured academic performance by calculating grade-point averages (GPA).
Kantomaa and colleagues found that at age 8, boys were significantly more likely to have compromised motor function than girls (P<0.001).
At 16, girls had higher academic achievement, with a mean GPA of 8.1, compared with 7.5 for boys (P<0.001).
On the other hand, mean MET hours per week were 32.8 for boys and 28.7 for girls (P<0.001).
Finally, boys were significantly more likely to be overweight or obese than girls (P=0.001).
Using structural equation models, the researchers found that physical activity was associated with a higher GPA, and obesity was associated with a lower GPA.
Importantly, they reported, compromised motor function in childhood had a significant indirect effect on adolescents' academic achievement, through both physical inactivity and obesity but not via cardiorespiratory fitness based on the mean peak oxygen consumption VO2peak in mL/kg−1/min−1(49.1 among boys and 35.4 among girls, P<0.001).
The findings suggest that compromised motor function in childhood might play a causal role in poor academic outcomes later, Kantomaa and colleagues argued.