The primary purpose of this study was to determine if muscular endurance is affected by referenced waist circumference groupings, independent of body mass and subcutaneous abdominal fat, in women. This study also explored whether selected body composition measures were associated with muscular endurance. Eighty-four women were measured for height, weight, body mass index (BMI), waist circumference (WC), and abdominal skinfold thickness (SFAB) and performed 60-s sit-ups (SU) and maximal push-ups (PU) tests. Mean differences in SU and PU scores were tested across three groups based on WC as follows: WCG1 less than 70 cm; WCG2 between 70 and 89 cm; WCG3 [greater than or equal to] 90 cm. There were no significant differences in SU and PU scores between WCG1 and WCG2. WCG3 had significantly lower SU and PU scores compared to the other groups. After adjusting for the influence of SFAB, BMI, and weight, the differences disappeared. The regression analysis revealed a two-variable (BMI and SFAB) model that accounted for the variation in SU performance. For PU, only BMI loaded into the regression model. The results of this study suggest that women with a WC [greater than or equal to] 90 cm have decreased muscular endurance compared to their lower WC counterparts. This difference is related to higher body masses. (Contains 5 tables and 2 figures.)