Intra-abdominal Pressure and Pelvic Floor Health: Should We Be Thinking About This Relationship Differently?

Abstract

Intra-abdominal pressure (IAP) increases during physical activity. Activities with high IAP are often restricted for women because of potential pelvic floor overloading. Researchers categorize high IAP activities using absolute values (in centimeters of water). Although essential for descriptive purposes, absolute IAP may not be ideal for individualized exercise recommendations. For oxygen consumption, a well-established measure of fitness, exercise scientists use a percentage of the maximal value observed during exercise to create relative exercise intensity prescriptions for an individual. Relative exercise intensity correlates inversely to the maximal value observed. We explore whether this approach and response pattern extend to IAP observed during exercise. Fifty-five women completed 16 exercises while wearing a vaginal sensor to measure IAP. The highest mean IAP occurred during seated Valsalva/strain (IAPSTRAIN). We calculated relative IAP (in percent) for each participant by dividing the maximal IAP during each exercise by IAPSTRAIN. We examined relationships between relative IAP and IAPSTRAIN for each activity using Pearson r correlations. Mean age was 30.4 ± 9.4 years, and body mass index was 22.4 ± 2.6 kg/m. For most women, IAP was greater during strain than during exercises. Relative IAPs negatively correlated with IAPSTRAIN. Excluding one exercise because of small sample sizes, r for all others ranged from -0.35 to -0.80, all statistically significant. The relative IAP responses to many exercises exhibit an inverse relationship to the highest IAP values during strain, consistent with other variables measured during exercise. Relative IAP may provide an alternative to absolute IAP in understanding IAP's effect on pelvic floor health.