Study design, materials and methods
This systematic review was pre-registered in an international registry. The conduct of the review followed established methodological standards. Embase, MEDLINE, CINAHL Complete, SPORTDiscus, and Web of Science were searched using a combination of terms related to physical activity as well as pelvic floor morphometry and function outcomes, including relevant anatomical structures. Studies published in English or French were eligible if they: (a) involved human participants of any population; (b) cross-sectionally compared at least two groups with differing levels of physical activity (e.g., more active vs less active or sedentary; athletes vs non-athletes); and (c) compared groups on pelvic floor morphometry or function outcomes. Record screening, data extraction, and methodological quality assessment (using the Joanna Briggs Institute checklist for cross-sectional studies) were conducted independently by two reviewers, with any disagreements resolved through team discussion.
Results
The search yielded 17,404 records. After removal of duplicates and screening of titles, abstracts, and full texts, 21 studies were included. All studies were conducted in adult female populations (n=2,325 participants), except for one study involving adult male mountain bikers (n=37 participants). The largest studied subgroup comprised nulliparous, premenopausal females under 55 years of age. The more active populations among females were multi-sport athletes (4 studies), high-impact athletes (2 studies), runners (2 studies), heavy lifters (2 studies), active-duty military personnel (1 study), females engaging in regular exercise during the peripartum period (4 studies) as well as younger (4 studies) and older (>60 years; 1 study) active females participating in various types of exercise. Outcome measures included digital palpation (n=7), intravaginal pressure measurement devices (n=10), intra-anal pressure measurement device (n=1), intravaginal dynamometers (n=3), surface electromyography (n=4), imaging techniques (n=5), and other clinician-assessed morphometric outcomes (n=2). Figure 1 presents a synthesis of findings according to outcome measure.
Interpretation of results
This study provides a comprehensive synthesis of the potential impact of physical activity on pelvic floor morphometry and function across diverse populations. Previous reviews have focused on female populations and specific physical activity exposures, with a limited range of outcomes, mainly related to symptom presentation. Our findings confirm the substantial heterogeneity across studies but also identify more consistent and inconsistent patterns in data based on outcome measures, study quality, and type of physical activity, offering potential explanations for discrepancies. The review highlights the underrepresentation of males, younger (child and adolescent) and older individuals, transgender populations, and parous females, limiting the generalizability of findings from largely nulliparous female cohorts. Although this systematic review is based on cross-sectional data, which limits causal inference between physical activity and pelvic floor outcomes, the findings provide a foundation for exploring the relationship between pelvic floor morphometry or function and symptom presentation, linking mechanistic observations with clinical outcomes. Robust mechanistic and longitudinal studies are needed to clarify causal relationships.