Vigorous-intensity physical activity helped predict bone mineral content at two skeletal sites in children and adolescents, according to research published online in Frontiers in Endocrinology.
Maturity and age did not modify the effect of vigorous-intensity physical activity (VPA) or moderate- to vigorous-intensity physical activity (MVPA) on hip and spine bone mineral content (BMC) in boys or girls during the course of a decade, according to researchers at the University of Iowa.
“Our research is perhaps the strongest work to quantify, via an objective measure, the positive association between everyday physical activities that youth freely choose to do and bone mass,” Kathleen F. Janz, EdD, told Endocrine Today.
“Every minute spent in vigorous-intensity physical activity was associated with twice the bone mass at the clinically significant regions of the hip and spine when compared to moderate- to vigorous-intensity physical activity,” Janz said.
Janz and colleagues from the university compared the effect of VPA and MVPA on BMC in 1,987 children aged 5, 8, 11, 13 and 15 years recruited from the longitudinal Iowa bone development study. All participants had at least two measurements after age 8 years.
The investigators measured MVPA and VPA (minutes per day) using ActiGraph accelerometers, body size and somatic maturity using anthropometry, and spine and hip BMC using DXA.
Sex-specific multilevel linear models — adjusted for weight (kilogram), height (centimeter), linear age (year), nonlinear age (year2) and maturity (pre-peak height velocity vs. post-peak height velocity) — were fit for spine and hip BMC.
The researchers tested interaction effects (PA x maturity, PA x age) and examined differences in spine and hip BMC between the least active (10th percentile) and most active (90th percentile) participants at each examination period.
More hip BMC was seen in both boys and girls aged 5 years in the 90th percentile for VPA than those in the 10th percentile (8.5% and 6.1%, respectively) with the differences dropping at age 15 years to 2% and 1.8%, respectively.
“Current public health campaigns are aimed at obesity prevention and reduction and emphasize MVPA; this approach is clearly not optimal for bone health,” Janz said. “The known differences in types of physical activities for different targeted health outcomes, obesity vs. bone, suggests a need to promote physical activities that incorporate multiple motor skills, including soccer, tumbling and tennis, or promote diverse physical activity patterns.” — by Allegra Tiver
Disclosure: This work was supported by the National Institute for Dental and Craniofacial Research and the National Center for Research Resources