Marathon Series: The Injury That Doesn’t Announce Itself.
With the Melbourne Marathon this coming week we though we would talk about some common running injuries. Bone stress injuries have a habit of catching people off guard, and part of the reason is that we tend to go looking for them in the wrong place first. We check training load, we check shoes, we check the running surface. All reasonable places to look. But some of the strongest risk factors for a stress fracture have very little to do with the run itself, and everything to do with what’s happening in the athlete’s body in the background.
Sex is one of the clearest examples. Female runners carry roughly double the risk of male runners, and a large part of that gap isn’t purely structural, it’s driven by energy availability — whether the athlete is actually fuelling enough to support the training they’re doing. When the body isn’t getting enough energy in relative to what’s going out, one of the first systems to quietly downgrade is bone remodelling. It doesn’t necessarily show up as an obvious symptom. It shows up months later as a bone that couldn’t keep up with repair. The same picture, less commonly discussed, exists in male distance runners too, where a similar pattern of relative energy deficiency has been linked to a meaningfully higher injury rate.
Then there’s history. An athlete who has had a bone stress injury before, or who has a lower than expected bone density for their age, carries a materially higher risk of it happening again, in this bone or another one. That’s a conversation worth having early with anyone coming back from a previous stress fracture, not just a note in the file.
The biomechanical side of the picture is a little more familiar territory for us, but still easy to underweight. Runners with a naturally lower step rate, and those whose centre of mass bounces more than average with each stride, are showing up more often in the research as being at elevated risk. Excess pressure concentrated through particular parts of the foot, and a foot that rolls into eversion faster than typical, both point toward the same underlying theme — a small mechanical inefficiency, repeated tens of thousands of times over a training block, eventually asking more of a specific bone than it can keep pace with.
None of these factors are especially dramatic on their own, which is exactly why they get missed. A runner who trains sensibly and doesn’t have an obvious injury history can still be sitting on real risk if their energy intake isn’t matching their output, or if their bone density has never actually been checked. Taking a genuine history — training, menstrual, nutritional, injury — is doing as much of the risk assessment as anything we can pick up on a treadmill.
