6 Warning Signs of Stress Fractures Every Woman Should Know About
These key risk factors predict bone injury surprisingly well in women.
If you don't eat enough to support your workout, this will trigger a host of health problems, including weakened bones, which in turn will make you susceptible to stress fractures.
Everyone knows it, at least in theory. But it can be difficult to convince motivated runners that there is a direct cause-and-effect relationship between eating enough and the success of your subsequent training and health. A study published in the American Journal of Sports Medicine can serve as a helpful wake-up call.
The study followed 323 female athletes at Stanford in 16 different sports, including 47 long-distance runners. Through questionnaires and bone density scans, the athletes were evaluated as low, moderate or high risk according to the components of the "female athlete triad", which consists of "low energy availability (AE) with or without eating disorders, menstrual dysfunction and low bone mineral density ".
They then checked to see which athletes developed bone stress injuries, a continuum that runs from incipient "stress reactions" to stress fractures and, in worst cases, total fractures.
About half of the runners (24 of 47) were classified as low risk, and three of those athletes developed a bone stress injury - that's less than 13 percent.
Sixteen of the runners were at moderate risk, and half of them developed bone stress injuries in an average time of one year, meaning they were four times more likely to be injured than the low-risk group.
There were only seven high-risk athletes, and five of them developed bone stress injuries, meaning they were nearly six times more likely to be injured than the low-risk group.
Additionally, another pair of studies from Thomas Jefferson University in Philadelphia sought to identify overlooked physiological factors and lack of knowledge that contribute to stress fractures in running women. For example, "Compared to women without stress fractures, women with a history of stress fractures had increased their training load more rapidly," according to a news release. "In addition, although they knew of the importance of nutrition and strengthening exercises, women with a history of stress fractures more often reported that they did not have or did not have time for a balanced diet and adequate cross training to supplement their exercise regimen. race".
If you are an athlete in the moderate or high risk group, your chances of avoiding a season-ending injury are worse than tossing a coin. Modifying eating behavior can be tricky, but perhaps this information can help clarify what is at stake for some people.
What are the warning signs of a stress fracture?
Here are six signs (which had to be tweaked a bit based on the available data) that you may be at risk for developing a stress fracture, as outlined in a consensus statement published in the British Journal of Sports Medicine in 2014.
Low energy availability or loss of body weight, as a result of past or current eating disorders
Low body mass index (BMI)
Delayed first period (15 years or more)
Low bone mineral density
Previous stress fractures (or stress reactions)
This risk stratification protocol grew out of a series of conferences in 2012 and 2013, hoping to develop some standardized guidelines for getting back into the game. As Adam Tenforde, M.D., director of running medicine at Harvard University's Spaulding National Running Center and lead author of the study, points out, the new results show that the risks calculated using this method "are not theoretical."
What does this mean for you?
That is the hardest part. Just because someone is at higher risk doesn't necessarily mean they should stop training. It may be, for example, that some of the past risk factors that increase the risk score are already being addressed clinically.
Still, Tenforde offers four lessons for coaches and medical personnel:
Anyone in the moderate or high risk categories should be screened to make sure they are getting enough calories to support their training, along with calcium and vitamin D.
These athletes must be continuously monitored to ensure that these areas - nutrition, menstrual function, and bone health - continue to be addressed.
High-risk athletes may want to consider altering training by making low-impact cross training a more important part of their weekly routine, for example. Good sleep and recovery are important too, says Tenforde.
Not all stress fractures are the same. Most of the stress fractures in low-risk athletes occurred in the foot, perhaps a consequence of biomechanics and sport choice (since many of the low-risk athletes participated in other sports such as basketball, where jumping exerts a great force on the foot).
In the higher risk categories, on the other hand, many of the fractures occurred in places like the sacrum, pelvis, and femoral neck, where the bones tend to have a different and softer interior structure. These fractures may be less a direct consequence of biomechanical forces and more the result of weakened bone.
As a result, Tenforde suggests, an injury to one of those locations can be a warning sign that the athlete is at increased risk, so it should trigger an assessment of bone health, including a bone density scan.