Analysis of injury incidence in athletes throughout the phases of the menstrual cycle

Abstract

The incidence of injuries in female athletes may be influenced by hormonal fluctuations during the different phases of the menstrual cycle (MC). Therefore, the aim of this study was to investigate the occurrence of injuries among athletes from various sports disciplines across the phases of the MC. This is a cross-sectional, exploratory, and retrospective study, conducted through an electronic questionnaire distributed to university sports associations in Brazil. Of the 120 associations invited, 14 responded, totaling 100 athletes. The questionnaire was divided into four sections (sociodemographic data, training history, injuries, and gynecological conditions), allowing for the correlation of injuries with the phases of the MC. Statistical analysis was performed using Pearson’s chi-square test (χ²), with significance set at p < 0.05. The athletes had a mean age of 21.80 (±2.84) years, with 53% reporting at least one injury in the past 12 months. Injured athletes were younger (21.60 ± 2.85 years; p < 0.001), had less training experience (15.70 ± 13.20 months; p < 0.001), greater weekly training volume (2.98 ± 1.42 days; p < 0.001), and more annual competitions (3.92 ± 5.12; p < 0.001). Injuries were more frequent during the late follicular phase (45.3%; p < 0.001) and the luteal phase (34%; p < 0.001), predominantly joint-related and non-contact. No significant differences were found between contraceptive users and non-users (p > 0.05). It is concluded that the late follicular and luteal phases are associated with a higher risk of non-contact joint injuries. Longitudinal studies are recommended to further clarify how MC phases influence injury incidence in athletes.