Marta Erlandson is looking at how school-based activity can affect bone development for short- and long-term health benefits.

Strong kids, strong bones

Osteoporosis is a major public health concern later on in life, but preventing it or easing its severity comes much earlier—in the teens and early 20s. It is the only time skeletal bone can be increased, that is, while the body is still growing.

By University Communications
"During my PhD I studied recreational gymnastic participants and found that with one to two hours a week, children have better bone strength, especially at the forearm," said Marta Erlandson, assistant professor in the College of Kinesiology. "This finding is a big advantage, because the upper limb is the most common site of fracture in childhood, with roughly 65 per cent of all fractures being at the wrist."

The theory is if you can increase your peak bone mass— the amount of bone you have at the end of your growth period— you could reduce the risk of bone fragility and related fractures later in life.

Physical activity during the growing years has a beneficial impact on bone development with the most active children developing more bone compared to less active peers, but it is uncertain which type of exercise is most beneficial. While it has long been known that elite-level gymnasts have really good bone density, not everyone can participate 20 hours a week in sports.

"The type of exercise required to bring about the greatest benefits for bone development remains unknown," Erlandson said. "Most physical activity intervention programs have focused on lower limbs, paying little attention to upper limb exercises."

Backed by a Saskatchewan Health Research Foundation (SHRF) Establishment Grant, Erlandson is investigating the effect of a school-based physical activity intervention that challenges upper and lower limbs on bone development for both short- and long-term health benefits.

"Since we've shown that one to two hours of recreational level skills per week has a positive impact on bone health, we want to take that model into the school and work with teachers so they understand these gymnastic-type activities and how they can have a long-term impact on the bone health of these kids," she said.

Erlandson is working in partnership with the Saskatoon Public School Board to conduct this study. Two schools in the city have been purposefully sampled to have similar demographics, programming and social supports and have confirmed interest. Children in Grades 6 through 8 at school 1 will receive an eight-month weight-bearing physical activity intervention, while those at school 2 will receive conventional physical education programming.

"I will measure the children's bone density and structure before and after the intervention as well as one and two years later to see if these benefits are being maintained," Erlandson said.

Randomization is being done by school so that one school receives the intervention and the other receives regular classes to minimize the potential that children receiving the intervention will influence children receiving the regular programming.

It is important to look at the younger ages, because this will provide the knowledge necessary to identify whether physical activity and diet can increase people's bone health. Additionally, the research findings could point to whether specific exercises will prevent fractures or postpone the age at which people are starting to have deterioration of bone health later in life.

"We are looking at primary prevention in trying to decrease the burden on our health care system later in life," Erlandson said. "But bone is unique and we really can't do that in the 50s and 60s when the low bone mass shows up."


This story originally appeared in Research for Health, published by the Saskatchewan Health Research Foundation.