How exercise impacts bone health in adolescents, astronauts, and you!

Leigh Gabel's love of sports and exercise started with her participation in youth sports, an interest that eventually shaped her research focus on the impact of exercise on pediatric bone health.

Gabel’s interest in bone health stems from the skeleton’s distinctive ability to remember past movement. “Bones adapt to how they are loaded. Like an autobiography, our skeletons carry a lifetime of loading history,” explains Dr. Gabel, PhD, assistant professor in the Faculty of Kinesiology at the University of Calgary. “For example, we know that gymnasts, tennis players and baseball pitchers develop unique skeletal adaptations during their youth that persist through adulthood.”

With her interest in skeletal adaptations, Gabel leads research in optimizing bone development and musculoskeletal (MSK) health across the lifespan, focusing on how exercise and loading activities such as resistance training influence bone health, specifically in adolescents and astronauts.

Developing strong bones for life

“Childhood and adolescence are critical periods for skeletal development. You gain more bone mass in only a few years during adolescence than you will ever lose later in life,” says Gabel. “So, it is important to establish healthy lifestyle behaviours, such as nutrition and physical activity, at a young age to optimize bone health for life.”

While working on her PhD in experimental medicine at the University of British Columbia, she collected data using a large longitudinal study, measuring the daily movement behaviours of children with accelerometers. Using high-resolution imaging, the research team analyzed the relationships between physical activity and changes in bone structure and strength. The findings revealed that children who were active and engaged in vigorous physical activity frequently throughout the day had stronger bones.

How to optimize bone development

Gabel is building on her thesis research data to kickstart a study on the influence of physical activity loading patterns on skeletal development in healthy youth. She hopes to expand her research to different populations to understand how to optimize bone development for youth living with chronic conditions, including children with neuromuscular disease.

“Many chronic diseases are associated with poor bone health, largely due to reduced physical activity and mobility. In these cohorts, the focus is on preventing fractures and building a healthy skeleton because one fracture can drastically reduce mobility and quality of life,” explains Gabel.

With a research focus on bone development in adolescence, Gabel sees an opportunity to impact bone health across the lifespan. “Studying bone development across different populations presents a unique opportunity to understand the impacts of healthy behaviours, like daily exercise, that can help develop and maintain strong bones,” she says.

Bone adaptations in microgravity

Adolescence is not the only time where bones adapt to a highly changing environment — the effects of microgravity and weightlessness in space results in rapid changes to astronauts’ bones.

While completing her postdoctoral fellowship, Gabel was involved in the TBone study, led by Dr. Steven Boyd, PhD, director of the McCaig Institute for Bone and Joint Health, in the Bone Lab in collaboration with the Canadian Space Agency and NASA, which investigated the impacts of microgravity on bones. Their recent study measured the effects of pre-flight and in-flight exercise on bone loss in astronauts. The team used 3D imaging from high-resolution peripheral quantitative CT scans to assess bone structure and strength before flight and after returning from space. Findings revealed that bone loss progresses with the length of a space mission despite daily exercise programs designed to prevent bone loss.

The next stage of the TBone study is underway with the integration of multiple international studies. “TBone2 focuses on even longer duration space missions (one year) and has a greater emphasis on how bone recovers. With the collaboration of multiple studies, the next stage will provide insight on how different body systems change and influence one another during a space mission,” explains Gabel.