This is NOT a high Impact bra.  This is perhaps the shell that would go inside my other actual atheltic bras I use to run and do HIIT classes in.  The material is as thin as my standard bra.  I'm a size 10 / 34D and I almost had to leave my HIIT class early from the lack of support.  My girls and I  certainly put on quite the show.  And an equally lovely surprise;  the dye ran the first several washes and ruined my tanks everytime I sweat - which is why I go to gym and classes.  Bra also dyed my towels gray.  Yes I can wear it to yoga and it compliments my racerback tanks, but do not market it as High Impact - waste of money.