What Pad Weight Gain During Treadmill Running Indicates Urine Leakage Among Females? An Observational Study

Pad tests have been used to assess urinary incontinence (UI) during exercise, but they do not account for confounding factors such as perspiration. The objectives of this study were to describe pad weight gain among runners with and without running-induced stress UI (RI-SUI), who complete a standardized treadmill-based pad test, and to investigate the sensitivity and specificity of pad weight gain as a measure of urine leakage.

This was an observational cohort study. We recruited adult female runners with and without RI-SUI. Participants performed a 38-min treadmill-based running protocol while wearing a pre-weighted incontinence pad. Pad weight gain was described by group, then compared between groups using the Mann-Whitney U test. A receiver-operating characteristic (ROC) curve was used to evaluate the sensitivity and specificity of different cutoff values for pad weight gain.

Data from 74 runners (20 with and 54 without RI-SUI) were included. The median pad weight gain was significantly higher in the incontinent group (24.20 g; range 3.90-166.30 g) than in the continent group (3.80 g; range 0.20-19.96 g; p < 0.001). When using a 9.35 g cutoff, the ROC curve predicted urine leakage with 70% sensitivity and 88% specificity, while a 0.25 g cutoff would achieve 100% sensitivity and 19.98 g would achieve 100% specificity.

Pad weight gain during a treadmill-based pad test should be interpreted cautiously, as values up to 19.96 g may result from perspiration or other fluids.