Researchers have a prescription for improving the health of America’s teens: Get more exercise at school.
Public health experts recommend that kids spend at least 30 minutes of the school day engaged in moderate to vigorous physical activity. That would get them halfway to the goal of exercising for at least an hour each day.
To make that happen, schools would need to devote 7.5 percent of their instructional time to physical fitness. Instead, students are spending a mere 4.8 percent of the school day — or 23.2 minutes — improving their bodies instead of their minds, according to a study published Tuesday in the journal Pediatrics.
“Because adolescents spend so much time at school, even a small increase in the proportion of at-school time spent physically active could lead to meaningful increases in overall physical activity and metabolic health,” the study authors wrote.
American teens have a reputation for being among the most sedentary in the world, with only 8 percent getting the recommended 60 minutes of exercise a day. That exercise deficit sets them up for a host of chronic diseases, including diabetes and heart disease. It also saps their brainpower and causes their grades to suffer, studies show.
To see when and where teens were (and weren’t) getting exercise throughout the day, researchers outfitted 549 volunteers from Seattle and Baltimore with GPS monitors and activity trackers. The trackers recorded their location and their movement once every 30 seconds for about a week.
The volunteers — all between the ages of 12 and 16 — spent more of their waking hours at school than anywhere else, according to the GPS readings. On average, they passed 42 percent of their time at school, 28 percent at home, 13 percent in their neighborhoods, 4 percent near their schools and the rest elsewhere.
Meanwhile, the activity trackers revealed that the students averaged 39.4 minutes of moderate to vigorous physical activity over the course of each day. On school days, 55 percent of those minutes were tallied at school. When weekends were factored in, 42 percent of the week’s total exercise occurred on school grounds. The amount of time teens spent exercising was more than 25 percent higher on school days than on weekend days, according to the study.
Although schools accounted for biggest share of total exercise, they were also the places where teens were most likely to be sedentary. Over the course of an entire week, only 4.8 percent of time at school was spent getting exercise. That compared with 5.3 percent of time at home, 9.5 percent of time in one’s neighborhood, 9.7 percent of time near school and 7.1 percent of time in other places.
In each of these locations, boys got more exercise than girls, the researchers found. Policymakers should keep that in mind when designing programs to boost physical fitness among teens, the study authors wrote.
The analysis turned up no differences in exercise patterns based on teens’ race or ethnicity, or whether their parents had a college degree.
In addition to endorsing more physical education at school, the researchers suggested that teens spend more time in the areas near their homes and schools, since those were places where teens tended to be more active.
“Increasing time in home and school neighborhoods might increase physical activity, partly by reducing time spent in less active locations,” they wrote.
