A comprehensive review conducted by the International Osteoporosis Foundation (IOF) emphasizes the importance of reducing sedentary behavior to enhance bone health across all age groups. The analysis reveals that replacing sitting time with even light activity can significantly protect against fractures and bolster bone health.
The review, led by Professor Olivier Bruyère, Co-chair of the IOF Rehabilitation Working Group, scrutinizes numerous studies to establish a clear connection between physical activity, sedentary habits, and bone health. “This review highlights a critical message for populations worldwide: bone health depends not only on engaging in regular physical activity but also on reducing the hours we spend in sedentary behavior,” Bruyère stated.
The research examined two vital outcomes: bone mineral density (BMD) and fracture risk. BMD, which measures the mineral content within bone, is a critical indicator of bone strength. The Working Group’s findings suggest that all age groups, from children to older adults, can benefit from increased movement and reduced sitting time.
Impact on Different Age Groups
For children and adolescents, prolonged sedentary behavior, particularly from screen time, is linked to lower BMD at key weight-bearing sites such as the femoral neck. The review found that engaging in weight-bearing activities like running, jumping, and resistance training during growth phases can significantly enhance bone mass. Furthermore, early interventions through school-based activity programs have shown lasting benefits but require ongoing participation to maintain their effectiveness.
In adults, regular physical activity, especially moderate-to-vigorous weight-bearing exercises and resistance training, is associated with higher BMD and a decreased risk of fractures. The research indicates that sedentary behavior correlates with lower BMD, particularly in areas such as the hip and pelvis. Notably, prolonged sitting is more detrimental than shorter periods of inactivity.
Older adults also experience pronounced benefits from even light physical activities, such as walking or household chores, which can improve BMD and minimize fracture risk. The review highlights that older adults who engage in sedentary behavior are especially vulnerable; replacing just 30 minutes of sitting with light activity can measurably improve bone health, particularly in women over 50.
Guidelines for Optimal Bone Health
The findings underscore the independent effects of physical activity and sedentary behavior. Simply being active does not negate the negative impacts of excessive sitting. Even modest adjustments, such as substituting sitting with movement, can yield significant benefits. The World Health Organization guidelines align closely with these insights, recommending 60 minutes of daily physical activity for children and 150 to 300 minutes per week for adults, while also advocating for reduced sedentary time across all demographics.
In a joint statement, Professor Nicholas Harvey, President of the IOF, and Eugene McCloskey, Chairman of the IOF Committee of Scientific Advisors, emphasized the need for proactive measures. They urged governments and healthcare providers to implement extensive public health strategies that promote active lifestyles and systematically reduce sedentary behaviors to enhance skeletal health and prevent fractures.
While the review presents significant findings, it does have limitations. Many studies relied on self-reported data regarding physical activity and sedentary behavior, which can be less reliable than data gathered from wearable devices. Additionally, factors such as nutrition, body weight, and sex differences were not consistently accounted for, and some evidence regarding the independent effects of sedentary behavior on BMD in older adults was inconsistent.
Despite these limitations, the study’s conclusions offer valuable guidance for healthcare practices. Medical professionals are encouraged to assess patients’ physical activity levels and sedentary behavior during routine visits, prescribing movement similarly to how medications are prescribed. Public health policies should focus on creating environments conducive to physical activity, including walkable cities and accessible recreational facilities.
In summary, the research highlights that maintaining active lifestyles is crucial for bone health, while excessive sitting poses significant risks. Simple changes that promote light daily activity can be instrumental in safeguarding bone health and reducing fracture risk throughout life. The study was published in the journal Calcified Tissue International.
