I am a size 4 (125 lbs) and 34B and I purchased size 34B in this bra.  The colours were great but the fit was somewhat small and the straps were particularly short and dug into the shoulders.  I also am unsure if the bra is suitable for running as there are no vents on the bra and at the end of my run the bra is 'soaked' and leaves an uncomfortable feeling.  There are also lumps as one reviewer pointed out, along the front seams that do not smooth out under clothing (but this is a minor issue for me).  I love the colours but I would hesitate before purchasing another one.