Overview
- Researchers tracked 33 FC Barcelona Femení players across four seasons and recorded 80 lower‑limb injuries, 11 of which occurred on bleeding days.
- After accounting for exposure time, injury incidence was similar on bleeding and non‑bleeding days, but injuries during bleeding led to roughly triple the days lost.
- Soft‑tissue injury burden was markedly higher during bleeding days, with 684 versus 206 days lost per 1,000 training hours.
- Authors recommend cycle tracking and modest training adjustments such as longer warm‑ups, moderated high‑speed work, and added recovery rather than avoiding training.
- The single‑club sample and lack of hormone, iron, sleep, nutrition, and symptom data limit conclusions, though hypotheses include effects of low estrogen, iron loss, fatigue, and inflammation.