Injury is a continuum, not a switch

Medium confidence

Injury is not simply on or off. In interviews, runners described five to nine steps between feeling fine and hurting enough to stop. Most of the time you sit somewhere in the middle, not at either end.

Why it works

Stress builds up in muscles and tendons and eases off again all the time. The point where a runner decides to call it an "injury" is a personal line, not a real edge, so the tissue underneath is really changing by degrees.

What it means in practice

Track symptoms with more shades than a simple injured/not-injured toggle. Help runners notice the early-warning steps before real pain sets in. And in customer-facing copy, talk about how the body feels right now rather than the injured/healthy binary.

The evidence

  • Lacey, A., et al. (2023). The Running Injury Continuum: A qualitative examination of recreational runners' description and management of injury. PLoS ONE.

    Across 7 focus groups, 31 recreational runners described injury as a 9-level continuum, from injury-free to career-ending. They placed each level in four descriptor categories: physical, outcome (effect on running and daily life), psychological, and management. Runners trained through the lower levels of early signaling, niggles, and mild discomfort, and self-classified as "injured" only when they needed a healthcare consultation or had to stop running. Lacey and colleagues propose the continuum as a tool for injury surveillance and risk-factor research, and as a framework for teaching runners to self-manage lower-level symptoms.

    n=31

Why we call confidence medium

In a 2023 qualitative study, Lacey interviewed 31 recreational runners and mapped a 9-level continuum, from "running smooth" through a range of symptom states to a time-loss injury. The interviews support the continuum framing well, but putting firm quantitative numbers on those levels is still ongoing.

Where it applies

Adult recreational runners.

Does not apply to: acute traumatic injuries (e.g., ankle sprain from a misstep) which are genuinely binary.

Plans that respect this

Last reviewed Apr 30, 2026. See how we score.