If we needed another argument for having an active childhood, here it is: A new long-term study says that active kids tend to grow up with stronger bones, even if they're more sedentary as teenagers. Dishearteningly, the same study reminds us that among teens, the inactive lifestyle is becoming endemic.
Researchers for the Iowa Bone Development Study recruited 530 kids to measure their physical activity intermittently over the course of 12 years. When the participants turned 17, they were scanned to measure the density, strength, and brittleness of their bones. The scans revealed that the most active participants had the strongest bones.
"Even once kids became less active, those who had been active had better bones," lead author Kathleen Janz told Reuters. That's not to let them off the hook—their bones could be even stronger if they'd move more. Most participants showed a concerning drop in physical activity as they got older, averaging about 24 minutes a day for 17-year-old girls and 36 minutes a day for 17-year-old boys. "Activity declines dramatically during adolescence, which is ironically a time when bone is most responsive to activity," Janz said.
No matter how common knowledge the argument for an active childhood seems, it's worth harping on—and maybe getting a little creative about. The latest attempt: Fourth-grade classrooms in (where else?) Portland, Oregon, have replaced chairs with exercise balls to help students focus and maybe even get in some core strength.
The students report that they enjoy swaying, moving from side to side, or bouncing whenever they find themselves getting bored with lessons. If they misbehave, it's back to normal chairs. "Balls are a privilege," a poster reminds the students.
The exercise balls have been an overwhelmingly positive change. "It makes learning just a little bit easier for them," teacher Liberty Looney says. "I think it's an opportunity to address not only behavior, but improved academic success and respond to the health needs of our society." Maybe the idea will catch on elsewhere. Denise Schilling, an associate professor at the Western University of Health Sciences who has done the first research on exercise balls in the classroom, seems to think so. "The balls are the way of the future," she told the Oregonian. If it keeps kids moving, we'll support it.