Lack of physical activity could weaken bones in teens

University of British Columbia (UBC) researchers and the Centre for Hip Health and Mobility researchers used high-resolution peripheral quantitative computed tomography (HR-pQCT) and found that teens who are inactive tend to have weaker bones than those who are physically active.

The study published in the Journal of Bone and Mineral Research, focused on researchers who measured the physical activity and bone strength of 309 teenagers over a four year window—between the ages of 10 to 14 years old for girls and 12 to 16 for boys.

Leigh Gabel, lead author of the study and PhD candidate in orthopedics at UBC, and her co-investigators, used HR-pQCT to compare differences between the participants who met the daily recommendation of 60 minutes of moderate-to-vigorous physical activity per day and those who got less than 30 minutes a day.

"We found that teens who are less active had weaker bones, and bone strength is critical for preventing fractures," said Gabel in a statement.

Bone size, density and microarchitecture are what determine bone strength. Data suggests that boys had larger and stronger bones. However, both boys and girls responded in the same way to physical activity.

"We need school- and community-based approaches that make it easier for children and families to be more active," said co-author Heather McKay, a professor in orthopedics and family practice at UBC and the Centre for Hip Health and Mobility. "The good news is that activity does not have to be structured or organized to be effective: short bursts such as dancing at home, playing tag at the park, chasing your dog or hopping and skipping count, too."