I used my nursing bras through nursing all three of my kids though... so that's my contribution. (ecochildsplay.com)
Another few companies make «sports bras for nursing» but their positive reviews are based on lounging around the house or sleeping and not actually exercising. (rookiemoms.com)
For example: the older I get (lol I'm 23) the less interested I am in wearing bras with padding. (alreadypretty.com)