{
    "abstract": "To examine the incidence of injuries among different menstrual phases in eumenorrheic cycles and abnormal menstrual cycles in female athletes.\nThis prospective cohort study recruited female athletes involved in collegiate, semi-professional, or professional team sports. Participating athletes self-reported their menstruation during the follow-up period. Menstrual cycles were classified as polymenorrhea, oligomenorrhea/amenorrhea, and eumenorrhea. Eumenorrheic cycles were further divided into estimated follicular phase (EFP), estimated ovulatory phase (EOP), and estimated luteal phase (ELP). Time-loss injuries and sports participation status were recorded by team medical staff. Incidence rates for each cycle and phase category were calculated per 1,000 athlete-days with 95% confidence intervals (CI). Incidence rate ratios (IRR) were utilized to compare risks among cycle and phase categories.\nData from 316 female athletes were analyzed over a median follow-up period of 337 days. The incidence rates during eumenorrheic, oligomenorrheic/ amenorrheic, and polymenorrheic cycles were 3.10 (95% CI, 2.61-3.67), 2.11 (95% CI, 1.44-2.98), and 4.84 (95% CI, 2.77-7.86) per 1,000 athlete-days, respectively. Among eumenorrheic phases, the highest incidence rate was in the EOP at 5.14 (95% CI, 3.26-7.7), followed by the EFP at 3.19 (95% CI, 2.47-4.04) and the ELP at 2.52 (95% CI, 1.85-3.35). The incidence rate ratios (IRRs) for EOP compared to EFP and ELP were 1.61 (95% CI, 1.004-2.586) and 2.04 (95% CI, 1.238-3.357), respectively.\nInjury risk is significantly higher during the EOP compared to the EFP and ELP in eumenorrheic cycles. Injury incidence was found to be lower during oligomenorrheic/amenorrheic cycles than during eumenorrheic cycles. Future studies should explore the factors contributing to the heightened injury risk during the EOP and the observed reduction in injury rates during oligomenorrheic/amenorrheic cycles.",
    "authors": [
        {
            "affiliation": null,
            "firstname": "Miwako",
            "initials": "M",
            "lastname": "Suzuki-Yamanaka"
        },
        {
            "affiliation": "Euphoria Company, Limited, JAPAN.",
            "firstname": "Satoko",
            "initials": "S",
            "lastname": "Hashiba"
        },
        {
            "affiliation": "Euphoria Company, Limited, JAPAN.",
            "firstname": "Ryosuke",
            "initials": "R",
            "lastname": "Takahashi"
        },
        {
            "affiliation": "Nippon Sport Science University, Department of Exercise Physiology, Nihon Taiiku Daigaku, JAPAN.",
            "firstname": "Mikako",
            "initials": "M",
            "lastname": "Sakamaki-Sunaga"
        },
        {
            "affiliation": null,
            "firstname": "Hiroki",
            "initials": "H",
            "lastname": "Iizawa"
        },
        {
            "affiliation": "Baseball & Sports Medicine, JAPAN.",
            "firstname": "Naotaka",
            "initials": "N",
            "lastname": "Mamizuka"
        }
    ],
    "conclusions": null,
    "copyrights": "Copyright \u00a9 2025 by the American College of Sports Medicine.",
    "doi": "10.1249/MSS.0000000000003679",
    "journal": "Medicine and science in sports and exercise",
    "keywords": [],
    "methods": null,
    "publication_date": "2025-02-17",
    "pubmed_id": "39957054",
    "results": "Data from 316 female athletes were analyzed over a median follow-up period of 337 days. The incidence rates during eumenorrheic, oligomenorrheic/ amenorrheic, and polymenorrheic cycles were 3.10 (95% CI, 2.61-3.67), 2.11 (95% CI, 1.44-2.98), and 4.84 (95% CI, 2.77-7.86) per 1,000 athlete-days, respectively. Among eumenorrheic phases, the highest incidence rate was in the EOP at 5.14 (95% CI, 3.26-7.7), followed by the EFP at 3.19 (95% CI, 2.47-4.04) and the ELP at 2.52 (95% CI, 1.85-3.35). The incidence rate ratios (IRRs) for EOP compared to EFP and ELP were 1.61 (95% CI, 1.004-2.586) and 2.04 (95% CI, 1.238-3.357), respectively.",
    "title": "Incidence of Sports Injuries Across Menstrual Phases in Eumenorrheic and Abnormal Cycles in Japanese Female Athletes: A Prospective Cohort Study.",
    "xml": "<Element 'PubmedArticle' at 0x7885035bd030>"
}