School systems seeking to improve test scores should add a fourth "R" to their curriculum: aerobics. Being fit improves mental performance in kids, just as it does in older adults.

With many schools around the country cutting back on recess time in the hope of improving test scores, their strategy is misplaced, to say the least, according to the findings of a new study. Fitter kids actually do better on math and reading tests than their less fit classmates.

Researchers used elementary and middle school children's standardized reading and math test scores and physical measures like body mass index (BMI) and their times from a 15-20 meter run to evaluate their mental and physical performance. They also looked at whether or not the kids got free or reduced-cost lunches to determine socioeconomic status, a factor known to disadvantage students when it comes to academics.

How many more studies will be needed before schools will give recess the respect it deserves and make it a non-negotiable part of every school day?

Children who were aerobically fit were 2.4 times more likely to pass math tests than kids who were not as fit. They were 2.2 times more likely to pass reading tests. Even children receiving free or reduced cost lunches (who were also more likely to be overweight) were more likely to pass the tests than kids who were aerobically unfit.

Since aerobic fitness may be easier to change than socioeconomic status, the authors urge that efforts be directed accordingly — which does not include cutting back recess time.

"Schools sacrificing physical education and physical activity time in search of more seat time for math and reading instruction," the authors write, "could potentially be pursuing a counterproductive approach."

The study also supports the idea that fitness and body weight are not necessarily connected, since BMI did not have the same effect as aerobic fitness. Earlier studies have also suggested that it’s more important to be fit than to be thin.

Schools that have cut back recess in an effort to focus more resources on academic performance will need to reconsider the shortsightedness of their efforts as more and more studies are supporting the important role of physical activity in cognitive and mental health. One wonders how many more studies will be needed before schools will give recess the respect it deserves and make it a non-negotiable part of every school day.

The study was carried out by researchers at Lincoln Public Schools and Creighton University in Nebraska, and published in the Journal of Pediatrics.