A simple morning walk to school can reduce stress reactivity in children during the school day, curbing increases in heart rate and blood pressure that can lead to cardiovascular disease later in life, says a new study by scientists from University of Buffalo.
The researchers found that children who took a simulated walk to school later experienced smaller elevations in systolic blood pressure, heart rate and perceived stress while taking a short exam than children who had gotten a simulated ride to school.
Cardiovascular reactivity-including changes in heart rate and blood pressure due to stress-is associated with the beginnings of cardiovascular disease in children, and atherosclerosis-the dangerous build-up of cholesterol, calcium, fat and other substances in artery walls-in adults.
"We know that physical activity has a protective effect on the development of cardiovascular disease, and one way it may be doing so is by reducing stress reactivity," he added.
Roemmich said because it's not known how long the protective effect of a bout of exercise lasts, parents and educators should promote active play time throughout the day.
"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.
"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," Roemmich added.
Roemmich said his study is the first to show that moderate-intensity exercise can reduce children's cardiovascular reactivity during later, stressful activities. The research builds on his earlier work, which demonstrated that higher-intensity interval exercise could afford similar protection in children.
The study appears in the August 2010 issue of Medicine and Science in Sports and Exercise.