Relationship of heart rate, perceived exertion, and intra-abdominal pressure in women

Exercise increases intra-abdominal pressure (IAP) acutely, which may impact the pelvic floor of women. IAP during exercise demonstrates high variability among women but is not routinely assessed. Assessing less invasive measures related to IAP during exercise may facilitate study of how IAP impacts the pelvic floor.

The objective of this study was to investigate the relationship of heart rate and rating of perceived exertion (RPE) with IAP during a standard treadmill test. We describe the trend of IAP by predicted aerobic fitness during incremental exercise. IAP was measured using a validated transducer placed in the upper vagina. Heart rate and RPE were collected during the first 3 stages of the standard Bruce treadmill protocol. Relationships of heart rate and RPE with IAP were determined by Pearson correlation coefficients. Predicted aerobic fitness values for each participant were ranked in tertiles with IAP by treadmill stage.

Twenty-four women participated in this study (mean age: 24.7 (5.4) years; body mass index: 22.5 (2.2) kg/m²). There were significant relationships between heart rate and IAP (r= 0.67, p < 0.001) and RPE and IAP (r= 0.60, p < 0.001) across treadmill stages. Tertiles of predicted aerobic fitness and IAP displayed similar trends as other exercise measures during incremental exercise, such as, heart rate and ventilation.

Heart rate and RPE could be used as proxy measures of IAP during incremental exercise. Aerobic fitness may help explain IAP variability in women and provide context for future research on IAP and pelvic floor health.