THURSDAY, Feb. 28, 2013 (HealthDay News) -- One key to better grades in the classroom may lie in the gym or on the playground, a new study finds.
The research, to be published in an upcoming issue of the Journal of Pediatrics, found that elementary and middle school students who don't get enough exercise are more likely to fail math and reading tests.
Although the study didn't prove a cause-and-effect relationship, the findings may be especially important in light of the fact that some school districts in the United States have cut physical education classes in order to devote more time to the "3 Rs" (reading, writing and arithmetic), the researchers said.
"Schools sacrificing physical education and physical activity time in search of more seat time for math and reading instruction could potentially be pursuing a counterproductive approach," study lead researcher Dr. Robert Rauner of Creighton University and Lincoln Public Schools in Lincoln, Neb., said in a journal news release.
In the study, Rauner's team compared fitness levels and test scores among students in elementary and middle schools in Lincoln and found that aerobically fit students were 2.4 times more likely to pass math tests and more than twice as likely to pass reading tests than those who were not aerobically fit.
The researchers also found that body-mass index (a measurement of body fat based on height and weight) was an important indicator for overall general health, but did not have a significant effect on test scores, according to the study.
So although obesity is a major concern for kids' health, the findings suggest that aerobic fitness may have an even greater effect on school performance than weight, the researchers said.
They also found that both aerobic fitness and family income have a similar impact on children's school performance. Since students' aerobic fitness can be easier to improve than household income, schools should think carefully before they reduce the time given to physical education classes and recess, the researchers suggested.
The U.S. Centers for Disease Control and Prevention has more about children and physical activity.