Low-support sports bras are usually designed for yoga, pilates, stretching, and light studio movement, where softness and comfort matter most. Medium-support bras need more hold for training, gym sessions, and daily activewear. High-support bras are developed for higher-impact movement and need stronger fabric recovery, coverage, underband stability, strap control, and construction support. The difference is not only fabric thickness. It is the full structure of the bra.