Stress Fractures (Bone Stress Injuries)

What it is

Bone is living tissue that constantly remodels — breaking down and rebuilding stronger in response to training. Bone stress injuries sit on a continuum from a mild *stress reaction* to a true *stress fracture*, and they happen when repetitive loading outpaces the bone's ability to remodel¹. In runners they show up most often in the shin (tibia), the foot (metatarsals), and the hip/pelvis or femur. The hallmark is *focal, pinpoint* bone pain — pain you can cover with one fingertip — that worsens with impact and, as it progresses, can ache at rest or at night.

Why runners get them

The usual driver is too much, too soon — a rapid jump in mileage or intensity with too little recovery. Bone remodeling *lags* the load that drives it by a matter of weeks, so a fast build outruns the bone's ability to adapt, and that gap is exactly when stress injuries develop¹.

One contributor deserves special mention: *under-fueling*. Not eating enough to match your training (low energy availability) weakens bone and is a well-recognized risk factor for bone stress injuries — part of what's called RED-S / the female athlete triad¹. Fueling adequately is a genuine part of staying healthy, not just performing.

The warning signs — and why they matter

This is the safety-critical part. Unlike muscle soreness, a bone stress injury tends to be sharp, focal, and pinpoint, it gets *worse* through a run rather than warming up, and it can hurt at rest or at night. Continuing to run on it risks progressing a stress reaction into a full fracture¹ — and a few sites (the front of the shin, the hip/ groin, the top of the foot) are higher-risk and slower to heal. If you suspect one:

• Stop running — don't try to train through pinpoint bone pain.
• Get it evaluated. Diagnosis usually needs imaging (MRI is most sensitive; early stress fractures often don't show on a plain X-ray).
• Treat night pain or pain at rest, or pain at a high-risk site, as a reason to seek care promptly rather than waiting.

How it's generally managed

Treatment centers on offloading the bone — relative rest, sometimes a boot or crutches for higher-grade or high-risk injuries — then a graded, progressive return once it has healed, while fixing the cause: the training-load error *and* any under-fueling¹. Recovery commonly takes weeks to a few months depending on the site and severity, and a clinician should guide both the timeline and the return to running.

When to see a professional

Any suspected stress fracture warrants assessment — focal or pinpoint bone pain, pain at rest or at night, or bone pain that doesn't settle within a few days of reduced load. Pain at a high-risk site (front of the shin, the hip or groin, the top of the foot) warrants prompt evaluation.