The trend presents an interesting conundrum for pediatricians as they attempt to get kids off of iPads and Xboxes and onto tracks and athletic fields: How much activity is too much? While highly active kids may be improving their cardiovascular health, they also run the risk of overuse injury, which in turn could prevent them from exercising altogether. “Athletes who sustain recurrent overuse injuries may stop participating in sports and recreational activities,” the 2011 National Athletic Training Association’s position statement on pediatric overuse injuries warns, “thus potentially adding to the already increasing number of sedentary individuals and the obesity epidemic.”
Surprisingly, the issue has not been the subject of a great deal of scientific inquiry, and for parents concerned about their young runners, there isn’t a definitive answer. While orthopedic surgeons have warned parents about the dangers of too many baseball throws and soccer kicks, they have been less definitive about running. So when should parents be wary of their children’s running? At present, medical professionals can only speculate about how much running is too much for young athletes.
The unresolved question is whether there are any long-term health consequences to endurance training and racing that would make events like half-marathons and marathons inadvisable for younger competitors. After all, children’s bodies have their own unique needs and considerations when it comes to physical activity. “Children are not small adults,” cautions a position statement in the Clinical Journal of Sports Medicine titled “Children and Marathoning: How Young Is Too Young?” “Their anatomy and physiology are developing and not fully mature.”
As youth participation in running continues to rise, medical professionals are concerned that injuries will rise along with it. Running by its nature is a repetitive sport, one that involves thousands of collisions with the ground, and the risk of injury at any age is proportional to the number of miles run—even among adult runners, the annual injury rate can be as high as 70 percent. Because the growing areas of children’s bones are vulnerable to injury in the formative years, they may be even less able to withstand the repetitive stress of marathon running or training.
Highlighting the differences between younger and older runners, a recent article in the Journal of Athletic Training revealed that children don’t absorb the impact of running as well as adults. While the researchers were unable to identify a specific reason for the differences, the health implications are worrisome: Like a car with bad suspension, less absorption equals greater impact to bones, joints, and soft tissue, possibly leaving children more at risk for overuse injury.
Other studies have established that, compared to adults, children run with different mechanics and have shorter legs in relation to their body size, elements that may contribute to a diminished ability to absorb impact. Dr. Cordelia Carter, a pediatric orthopedic sports surgeon and researcher at Yale University, says, “Kids are still figuring out how to move and their bodies don’t yet have the strength and muscular control of adults.”