Bone Health in Endurance Athletes: Runners, Cyclists, and Swimmers
Key Findings
Weight-bearing exercise is widely recognised to benefit long-term bone health
Endurance sports place many athletes at a relative disadvantage for bone health because of their bone-loading characteristics and energy expenditure
Adolescents and adults in endurance sports such as running, and in non-weight-bearing sports such as cycling and swimming, often have lower BMD than ball- and power-sport athletes — sometimes lower than inactive peers
Low BMD increases the risk of stress and fragility fractures, both while competing and later in life
The review covers the variable bone effects of distance running, cycling, swimming and triathlon; evaluation of stress and fragility fractures; and diagnosis, management and prevention of low BMD in endurance athletes
Full text; not checked against the abstract: the levers discussed are impact/axial loading, energy availability and calcium/vitamin D status
Practical Application
Narrative clinical review: endurance athletes — runners included, and especially cyclists and swimmers whose sport does not load bone — often have lower bone mineral density than ball- and power-sport athletes and sometimes than inactive peers, which raises stress- and fragility-fracture risk now and later in life. Fitness alone does not protect bone; the sport's loading pattern and energy expenditure do the damage.
Not from this paper; the base's own practice: a cyclist or swimmer needs an osteogenic stimulus from outside the sport — axial-loaded strength (squat, deadlift), plyometrics (REF-518) or some running
Low energy availability compounds the risk ([REF-341-345]): bone is an early casualty of underfuelling, and non-impact sport plus LEA is the high-risk profile
Not from this paper; the base's own practice: check vitamin D (REF-355) and calcium intake; consider a DEXA scan after a long history of non-impact sport, especially for a masters athlete
When adding running to a non-impact background, progress volume slowly — the review names stress fractures as the consequence of low BMD
Limitations
2012 narrative review; more recent data may refine prevalence estimates; no numbers in the abstract
Observational associations (endurance sport ↔ low BMD) — causality confounded by self-selection/body composition
Does not separate masters 50+ (whose risk is even higher)
How this entry was checked and changed
Why this level
regraded 2026-09-27 from B+: narrative review without systematic method; the abstract carries no data
Content correction 2026-09-27
"Running (impact) protects; cycling and swimming do NOT" -> the abstract groups runners WITH cyclists and swimmers as often having lower BMD than ball/power-sport athletes and sometimes than inactive peers; running is not singled out as protective. Lead bullet corrected.
"Road cyclists show a high prevalence of osteopenia", "calcium loss via sweat", "stress-fracture risk factors: vitamin D/calcium deficiency, abrupt load increases" -> not in the abstract; removed or labelled as the base's own practice/full text.
Level B+ -> C+ per KB-LEVEL-RUBRIC (narrative review without systematic method). Sport line adds triathlon (covered by the review).