A study observed a correlation between moderate to vigorous physical activity performed early in life and stronger hips later in life. The correlation between light activity and hip strength was less clear.
“The unique availability of repeated accelerometer assessments over many years beginning at age 12 within the Children of the 90s cohort, allowed us to describe the trajectory of time spent in different physical activity intensities through early life and to examine how this might relate to adult hip strength,” said lead study author Ahmed Elhakeem, PhD, in a press release. “The results highlight adolescence as a potentially important period for bone development through high intensity exercise, which could benefit future bone health and prevent osteoporosis in later life.”
Bone strength peaks in early adulthood, Dr. Elhakeem and coauthors explained, and could be indicative of osteoporosis risk.
Study recruitment began during pregnancy and included women whose expected delivery date fell between April 1, 1991, and Dec. 31 1992; the final analysis included 2,569 healthy participants (62% were female). All participants had valid physical activity measurements for at least one age—12, 14, 16, and/or 25 years—and accelerometer assessments were replicated up to four times, once per age-associated clinical visit. The main outcome was femur neck bone mineral density (BMD) at 25 years, which was ascertained through radiographs.
At every age, males spent more time in moderate to vigorous-intensity activity; in adulthood, femur neck BMD was greater in males than females. The researchers stratified participants into three moderate to vigorous-intensity and three light-intensity trajectory subgroups for both sexes. For the moderate to vigorous-intensity trajectories, 85% of males were in the low adolescent group, 6% were in the high early adolescent group, and 9% were in the high mid-adolescent group. For females, moderate to vigorous-intensity trajectories were stratified into low adolescent-low adult (73%), low adolescent-high adult (8%), and high adolescent (19%) subgroups. For males, femur neck BMD was higher in the high early-adolescent subgroup (0.38 g/cm2) and the high mid-adolescent subgroup (0.33 g/cm2) than the low adolescent group (reference). For females, femur neck BMD greater in the high adolescent subgroup (0.28 g/cm2) compared to the low adolescent-low adult group (reference), but the low adolescent-high adult group had a femur neck BMD of −0.12 g/cm2.
“The light-intensity trajectories were not associated with femur neck BMD; for example, differences in femur neck BMD between the high decreasing and low nonlinear subgroups were 0.16 g/cm2 (95% CI, −0.08 to 0.40 g/cm2) in male participants and 0.20 g/cm2 (95% CI, −0.05 to 0.44 g/cm2) in female participants,” the authors noted.
The study was published in JAMA Network Open.
Dr. Elhakeem and colleagues concluded, “Our findings suggest that higher-intensity physical activity, along with potential bursts of higher-impact activity, throughout adolescence may be important for maximizing peak hip strength during early adulthood. If replicated in independent studies, these findings suggest that children’s involvement in moderate to vigorous–intensity physical activity may be beneficial for lasting bone health.”