For 72% of women, running is associated with discomfort caused by inadequate sports bras, resulting in insufficient support or excessive compression. Research indicates that unsupported breasts can move up to 19 cm during running, generating forces equivalent to those experienced by F1 drivers. Furthermore, over 90% of women wear sports bras that do not fit correctly, highlighting a critical gap in functional apparel design. Conventional elastane-based materials offer only a fixed level of support and compression, creating a trade-off between comfort and performance. To address this limitation, RHEON Labs has developed and commercialized a range of highly strain-rate-sensitive (SRS) polymers. These advanced polymers are characterized by their soft and elastic properties at rest, which transform to high stiffness and energy absorption under dynamic loads. This property enables the production of both thin films and elastic fibres that provide dynamic, adaptive support in performance apparel. For example, thin SRS films, as applied in the adidas Olympic sprint suit for Team GB, are heat-laminated onto textiles to create garments that deliver comfort during rest and enhanced muscle support and damping during high-impact activity. Melt-extruded SRS films and fibres are also employed in sports bras, enabling soft tissue damping and dynamic support. Independent testing conducted at the University of Portsmouth demonstrated that sports bras featuring RHEON Film patterns reduce breast displacement by 15%, effectively upgrading medium support at rest to high support under running conditions, without increasing discomfort. This presentation will detail the underlying material science of SRS polymers, their processing into films and fibres, and their integration into sports bras and high-performance apparel.