In this age of video games, tablets and smartphones children are becoming fatter and more sedentary than ever before. Kids are naturally active, but there are increasingly tempted to become couch potatoes.
A Canadian study found that inactivity can lead to weaker bones in teens.
South African guidelines suggest that children get a total of at least 60 minutes of moderate to heavy exercise each day, but research suggests that fewer than half do, with teenagers
being the worst.
Researchers reviewed physical activity and bone strength in more than 300 teens over a four-year period that is important for healthy bone development – ages 10 to 14 for girls and ages 12 to 16 for boys.
The study was published in the Journal of Bone and Mineral Research.
During those years, up to 36% of the skeleton is formed, and bone is particularly responsive to physical activity, the researchers said.
"We found that teens who are less active had weaker bones, and bone strength is critical for preventing fractures," said lead author Leigh Gabel, a Ph.D. candidate in orthopaedics at the University of British Columbia.
Limiting screen time
"Kids who are sitting around are not putting weight on their bones in ways that promote bone strength," which is why teens need to engage in weight-bearing activities such as running and jumping and sports like soccer, ultimate Frisbee and basketball, Gabel said in a university news release.
Teens don't have to do structured or organised sports and activities to boost their bone health. Simple things such as dancing at home, playing tag at the park, chasing the dog or hopping and skipping are also effective, according to the researchers.
Parents and caregivers should limit teens' screen time and be good role models of an active lifestyle, said co-author Heather McKay, a professor at UBC and director of the Center for Hip Health and Mobility in Vancouver.
Active teens likely to be healthier
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Active parents, active kids