I'd go to a good running store, like Fleet Feet, approach one of the women there and ask to try on a bunch of stuff.

Anonymous wrote:Moving Comfart Fiona, hands down. Even has nursing-like straps that can come down.

This. Look no further. I was 38DD while nursing and was running comfortably in these.

Moving Comfart Fiona, hands down. Even has nursing-like straps that can come down.

Not a nursing mom anymore (DC is 8 YO), but reviews of my new favorite sports bra have mentioned that it is good for nursing moms. The straps adjust with velcro in the front. Moving Comfort Rebound Racer.
http://www.zappos.com/moving-comfort-rebound-racer-ebony-melange

I vaguely recall Title 9 having nursing bras, rated for activity level, so you might look at their site.

I used the ones that have 5 or so hooks down the front center. I actually ended up liking them better than regular nursing bras, so I ditched those and just used sports bras.

Any help would be appreciated. thanks!