Although this bra is very well constructed, and supports me completely no matter what my activity, I still must mention the fact that you CAN'T undo the bra in back and take it off.  You can undo the hook and eye closures, but the bra is designed to be completely sewn together even across the back.  Unhooking it simply gives you about 1/2 inch more room at the bottom edge to work with.  Great bra, but be ready to struggle.