Working out may help teens boost their grades, a new study suggests.
Adolescents who routinely engaged in moderate to vigorous exercise had long-term improvements in their academic performance, the British Journal of Sports Medicine study published on Oct. 22 reported.
"Our study suggests that the effect of physical activity may be quite large," John Reilly, a professor of physical activity and public health science at the University of Strathclyde in the U.K., told Bloomberg.
The researchers looked at a sample of about 5,000 children who were enrolled in a long-running study that tracks children born in the U.K. between 1991 and 1992.
When children reached the 11 years old, their daily physical activity levels were measured using an accelerometer for three to seven days. The device, similar to how a pedometer tracks steps, recorded the average time children exercised, which was 29 minutes a day for boys and 18 minutes for girls.
The Centers for Disease Control and Prevention in the U.S. recommend that children participate in physical activities for 60 minutes or more a day, which includes muscle and bone strengthening activities on at least three days per week.
"The actual levels of daily physical activity at age 11 were quite low," Reilly noted.
The children had their academic performance tested at ages 11 and 13 with compulsory national tests for students, and also at 15 or 16 with the General Certificate of Secondary Education (GCSE) exam. The tests judged the children's abilities in English, math and science subjects.
When factors that could affect academic performance including birth weight, mother's age at delivery and other socioeconomic factors were adjusted for, the results showed that the more children participated in moderate to vigorous physical activity, the higher their test scores were at age 11 in all three subjects. For girls, science scores were most strongly linked to exercise.
When they followed up with the kids at age 13, their academic scores were still linked to how much they exercised when they were 11 years old.
By the time the kids took the GCSE exam, each 17 minute per day increase in physical activity for the boys was linked to an improvement in their score. Every additional 12 minutes a day increase in exercise for the girls was linked to an increased score as well, especially in the science category.
The researchers concluded that this study could show that there are gender differences in how exercise affects the brain. They also called for more studies to look at academic benefits that could be derived if students exercised the recommended 60 minutes or more a day.
"If moderate to vigorous physical activity does influence academic attainment this has implications for public health and education policy by providing schools and parents with a potentially important stake in meaningful and sustained increases in physical activity," they wrote.