You must do this as a teen to keep your bones healthy in adulthood

Some kids are naturally drawn toward sports, athletics, and exercise from a young age. Plenty of other adolescents and teens, though, tend to shy away from organized sports and exercise in general.

The amount of time and effort an individual devotes to physical activity as an adolescent is, of course, a matter of preference. However, a new study from the University of Bristol finds that engaging in intense physical exercise regularly between the ages of 12 and 16 is associated with much stronger bones and hip strength by adulthood.

Also, researchers conclude that frequent moderate-to-vigorous intensity physical activity (MVPA) during adolescence can go a long way toward reducing one’s chances of developing osteoporosis later in life. Hip fractures are among the most common complications linked to osteoporosis.

Every person hits their peak bone mass, or the point in which one’s bones have reached maximum strength and density, at some point during early adulthood (roughly late teens through mid-twenties). A low peak bone mass is usually considered a warning sign that bone fractures can happen easily, and is also considered a predictor of osteoporosis later in life. 

So, in summation, this research suggests that staying very active during adolescence results in more robust peak bone mass come adulthood, consequently reducing the risk of both general osteoporosis and hip fracture.

This research project was made possible thanks to data collected by the Children of the 90s initiative. Back between 1991-1992, that project recruited over 14,000 pregnant women. Since then, the children born to those families have been periodically checked in on by researchers over the past two decades. One aspect of those follow-up assessments was physical activity.

“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. 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,” explains lead study author Dr. Ahmed Elhakeem, a Senior Research Associate in Epidemiology, in a university release. “We have also confirmed other studies showing that levels of MVPA decline through adolescence. Our findings show it is really important to support young people to remain active at this age”

For this study, data on 2,569 adolescents enrolled in the Children of the 90s project was used. Each of those kids had previously had their typical physical activity habits measured four different times (ages 12, 14, 16, and 25). Accelerometers (devices that measure movement) were used to record physical activity levels on these occasions. 

A close examination of all that data revealed that more time spent by an adolescent engaged in intense physical activity between 12 and 16 years old was associated with particularly strong hips by the age of 25 years old.

Comparatively, easier-going exercise habits showed a much weaker association with strong hips.

“The findings from this study are welcome as they provide further evidence that children need to be doing moderate to vigorous-intensity physical activity during their early adolescence to maximize bone strength in later life and reduce the risk of painful fractures. Supporting and encouraging young people to be more physically active needs to be a priority for bone as well as general health,” comments Francesca Thompson, Clinical and Operations Director at the Royal Osteoporosis Society.

What about adopting a more active lifestyle after adolescence? Will such a change have a similar effect on bone strength? According to this study, probably not.

Researchers say their data indicates that when it comes to ensuring strong bone health, it’s a good idea to start exercising as early in life as possible. Not only does the evidence suggest that adolescent exercise is more important for bone health than adult exercise habits, but it also points to early-adolescent (12-14 years old) exercise being more beneficial than late-adolescent physical activity.

As alluded to earlier, not all adolescents are drawn toward, or particularly enjoy, intense exercise or playing organized sports. Still, these findings make a strong case that getting in at least occasional bouts of intense exercise during adolescence can pay dividends a few decades later in terms of bone health and overall physical wellbeing.

The full study can be found here, published in JAMA Network Open.