This bra is comfortable and allows me to work out whether walking, doing tai chi or lifting weights. I have had no problem with the zipper coming open. It does give a uni-boob look, tho, but Im not sure any bra of this type wouldnt since the support comes from compression. I usually get a size medium for most shirts or tops but I ordered a large here and am glad I did. Im a 36D and the large is just right - snug but not tight. Since I wear a prosthesis, I was hoping I could remove one of the pads and insert the prosthetis, but the opening is too small. The prosthesis works anyway, but is right next to my skin. I might have to just make my own opening!