“Niggles” predict bigger injuries

Minor unresolved physical complaints — what runners often call 'niggles' — substantially elevate the risk of progressing to a full injury that interrupts training.

In plain English

A niggle is a small ache that lingers between runs but does not stop you yet. These often come right before the injuries that do stop you. In one study, carrying a niggle raised injury risk roughly 4 to 7 times.

Why it works

Niggles likely represent early-stage tissue stress that the runner hasn't yet remediated. Ignoring or running through them allows the underlying load mismatch to continue.

What it means in practice

Treat persistent low-grade pain as a meaningful signal, not just background noise. In Buena Vida-style logging, encourage runners to flag 'niggles' separately from acute pain and adjust training in response. When a runner reports a niggle, the recommendation is generally to back off intensity or volume for a week — not stop entirely, but clearly reduce.

The evidence

  • Whalan, M., Lovell, R., Sampson, J.A. (2019). Do Niggles Matter? - Increased injury risk following physical complaints in football (soccer). Science and Medicine in Football.

    Non-time-loss injuries ('niggles') strongly predict subsequent time-loss injuries. Risk of TL injury was 3.6 times higher when preceded by 'minor' non-TL complaint and 6.9 times higher when preceded by 'moderate' non-TL complaint within the previous 7 days. Predictive power was good (AUC 0.73-0.83; predictive accuracy 22.0-41.8%). Over a quarter of players reported a physical complaint each week that did not prevent training/match play (28% of compliant questionnaires). The minor complaints carry meaningful injury-warning information that current training systems often ignore.

    n=218

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

    Recreational runners describe injury along a 9-level continuum, from injury-free to career-ending injury. Each level is described across four categories of descriptors: physical description, outcome (effect on running and daily life), psychological description, and management. Lower levels of injury (early signaling, niggles, mild discomfort) are routinely trained through. Runners only self-classify as 'injured' when they need a healthcare-professional consultation or have to cease running. The Running Injury Continuum is proposed as a tool for both injury surveillance (researchers, healthcare professionals) and risk-factor research, and as a framework for educating runners about appropriate self-management of lower-level injuries.

    n=31

Why we call confidence medium

Whalan 2019 in football showed niggles raised subsequent injury risk 3.6-6.9x. Lacey 2023 Running Injury Continuum confirms qualitatively in runners that lower-level symptoms precede time-loss injuries. Direct prospective running data is more limited.

Where it applies

Adult recreational and trained runners.

Does not apply to: normal post-workout muscle soreness that resolves within 48-72 hours.

Plans that respect this

Last reviewed 2026-05-01. See how we score.