Old Navy Medium Support Powersoft Adjustable-Strap Sports Bra The Medium Support Powersoft Adjustable-Strap Sports Bra ($25, originally $30) offered me just the right amount of support for medium-impact activities. I never worried my boobs might fall out. I probably wouldn't use this bra for running if you have larger than a B cup — I'm a small C and like a higher neck on my sports bra when I run because it provides maximum comfort. Image Source: oldnavy.gap.com Medium Support Powersoft Adjustable-Strap Sports Bra $25 from oldnavy.gap.com Buy Now