Beyond Performance Fuel: Could Carbohydrate Intake Contribute to Bone Stress Injury Prevention in Endurance Athletes? A Narrative Review

Abstract

Introduction. Bone stress injuries (BSIs) occur when repetitive skeletal loading exceeds
the capacity of bone to repair accumulated microdamage. Low energy availability
is an established risk factor, but the independent contribution of carbohydrate availability remains uncertain.

Aim. This narrative review examines whether carbohydrate-based sports foods could contribute indirectly to BSI prevention by helping endurance athletes meet carbohydrate requirements.

Material and methods. A targeted search of PubMed/MEDLINE was supplemented
by citation tracking and searches of publishers’ and journal websites, including the Journal
of Education, Health and Sport, Quality in Sport, and Pedagogy and Psychology of Sport.
The search was updated between April and July 2026. Human studies of endurance exercise, carbohydrate feeding or restriction, fasted training, bone turnover, and bone injury were prioritized.

Results. Carbohydrate ingestion during prolonged running can attenuate acute changes in selected bone-turnover markers, whereas severe short-term carbohydrate restriction has been associated with lower bone-formation markers and a less favorable turnover profile. In one observational study, current fasted training, but not self-reported carbohydrate restriction, was associated with a higher incidence of bone injury. The evidence is derived mainly from small, short-term studies in men and relies on surrogate biomarkers. No randomized trial has shown that sports drinks, gels, chews, bars, or powders reduce imaging-confirmed BSI.

Conclusions. Carbohydrate-based sports foods should not be presented as bone-protective supplements or established preventive interventions. However, they may be useful as practical fueling options during prolonged or high-volume training.