Women prefer to wear a sports bra not only for exercising, but also during resting and daily activities, highlighting deficiencies in current sports bra designs. The purpose of this study was to design, develop, and evaluate a sports bra that offers responsive behavior, in terms of breast support and comfort, both during rest and running conditions. A biomimetic design framework guided the conceptual phase, and moisture responsive plant biomechanics offered a feasible functional model. Fourteen sports bras were developed and wear- tested using college athletes. The moisture responsive panels inside the bra absorbed the sweat generated during running, making the fabric thicker when wet (statistically significant via 3D body scanning results), while maintaining comfort and perceived breast support through sweaty conditions (confirmed via questionnaire results). Adjustments to the underbust band tightness should be pursued, aiming to further improve sports bra functionality, promoting women health and their lifestyles.