Now kids can tell their teachers that if they don’t get outside to play tetherball or romp on the jungle gym, they could have a heart attack!

This helpful bit of fact-based guiltsuasion comes from a just-released study from the University of Buffalo that found that kids who walk to school and get other kinds of exercise throughout the day get less stressed during tests. Less stress means a reduced risk of high blood pressure, heart disease and other cardiovascular woes later in life.

In the study of 20 boys and 20 girls ages 10 to 14, half were put in a situation that simulated being driven to school (they sat in a comfy chair and watched a slide show of suburbia passing by) and half saw the same slide show while walking a mile on a treadmill while carrying a 10-pound daypack. Then, after a 20-minute cool down — presumably to simulate getting to school, going to your locker and putting bubblegum on the teacher’s seat — the kids took an exam. The stress of the test caused the walkers’ heart rates to increase by three beats per minute while the kids who simulated getting driven to school saw their heart rates spike by 11 beats per minute. This reaction is called “cardiovascular reactivity,” and can be especially worrisome in childhood since the cardiovascular disease process begins when we’re kids, according to the project’s senior researcher, James Roemmich, associate professor of pediatrics and exercise and nutrition science at U of B (whose mascot is not a buffalo but rather a bull).

Roemmich cautioned that they don’t yet know how long the effects of walking to school might last into the day. Thus, kids shouldn’t rely entirely on it to curb their cardiovascular reactivity.

“If it only lasts a couple of hours, then it would be most beneficial if a child walked or biked to school, then had recess during school, as well as a break at lunch, so they had opportunities for physical activity throughout the day,” Roemmich said in an interview with Science Daily. “This would put them in a constantly protective state against stressors that they’re incurring during the school day, whether that be taking an exam, trying to fit in with peers or speaking in front of classmates.”

So, yet another argument for letting kids be kids during the school day rather than keeping them penned like veal-to-be. (Numerous previous studies have shown that kids who are more physically active do better academically.)

Can’t you just hear a little Freddie Sanford wailing to his teacher that he’ll have The Big One if he can’t hit the playground before the spelling test?