BUSTED! “70% of the support your bra provides actually comes from the band,” Fantegrossi explains. This is why it is so important that the band fits properly. If it’s too loose, your bra will ride up, and your cups (and what’s inside them!) will sink down, and vice versa. Fantegrossi describes this as the “see-saw-effect”- a helpful visual to help understand why the band of your bra is such a key support factor.