5 for having a rear clasp (I hate pulling sweaty bras over my head if I don't have to), and adequate medium support.  I used this on the treadmill for a brisk walk, but use a different high impact pullover bra to run.  But while it's very convenient to put on, the fit in the back is awkward and annoying.  It does not lay flat at the clasp, so that dropped it to a 3.  I wish I returned it right away.