Bone stress injuries: a workload problem
Every BSI is an "error" in the number × magnitude of bone loading cycles; refer, then rebuild with sensibly progressed loading
Key Findings
All BSIs in runners occur through an "error" in workload: the interaction between the number and magnitude of bone loading cycles exceeds the tissue's ability to resist repetitive loads. There is no single optimal bone workload but a range, depending on the situation.
Mature skeleton: optimal workload allows performance gains while minimising bone damage accumulation by sensibly progressing training, particularly training intensity.
Prepubertal athletes: bone adapts best to low repetitions of fast, high-magnitude, multidirectional loads introduced a few times per day; premature sport specialisation should be avoided so the skeleton is built to withstand multidirectional loading.
When indicated (e.g. after repeated BSIs), reducing bone loading magnitude — such as increasing running cadence — should be considered. Managing an individual's bone workload requires consistent monitoring.
From the review body (full text, checked 2026-09-28: author manuscript PMC8316280): beyond workload, poor bone health contributes — up to 40% of female adolescent cross-country runners have a spine aBMD Z-score below −1 and up to 50% meet criteria for disordered eating and/or report menstrual dysfunction (RED-S / Female Athlete Triad); a prior BSI puts an athlete at high risk of another; individual risk reflects rapid workload change interacting with biomechanics, psychology, physiology, musculoskeletal qualities and energy availability.The review does not stratify BSI sites into high- and low-risk and does not discuss calcium or vitamin D. Companion sources: Hoenig 2022 primer (DOI 10.1038/s41572-022-00352-y); Warden 2014 return-to-run guidance (DOI 10.2519/jospt.2014.5334) — neither checked against its abstract here.
Practical Application
This review's message: a BSI is a workload error (too many loading cycles × too much magnitude for the bone's current tolerance), so prevention is sensible progression — especially of intensity — and, after repeated BSIs, reducing loading magnitude, for example by raising cadence (REF-620).
Red flags → refer: localised bony tenderness, impact pain worsening through a run or present at rest/night, groin/anterior-shin/forefoot pain → stop running, medical assessment and imaging. Do not coach through a suspected BSI. (Not from this paper; the base's own practice.)
Limitations
Narrative review (Level C+); diagnosis and return timelines are clinician-led and site-specific; coach-education, not a treatment protocol. The abstract carries no numbers; the risk-factor list above is from the review body, which gives no site stratification.
How this entry was checked and changed
Why this level
regraded 2026-09-27 from C: narrative review without systematic method (rubric C+), from the Warden/Edwards/Willy bone-loading group
Content correction 2026-09-27
Level C -> C+ per the 2026-09-26 rubric (narrative review).
Key Findings rewritten around what the abstract actually says (workload error = number × magnitude of loading cycles; a range not a single optimum; progress intensity sensibly; prepubertal multidirectional loading; cadence to reduce loading magnitude; monitoring). Risk-factor and site-stratification lists kept but labelled as review body, not abstract.
Section pointers (§25, §49/§50, §51, §15) replaced with existing refIds; the red-flag list labelled as the base's own practice.
2026-09-28: lines labelled "full text; not checked" read against the open-access full text (author manuscript PMC8316280): 0 confirmed, 1 corrected (risk factors kept where the review names them, with its figures), 1 removed (high-/low-risk site stratification and calcium/vitamin D are not in this review).
2026-09-28: Limitations line aligned with the full-text check (PMC8316280): the site stratification was removed, so only the risk-factor list is attributed to the review body.