I ran 1 mile and did strength training. It held my girls in place the whole time! My boobs are a bit big for the inside bra, but the outside layer is pretty high and fits tightly, so I felt secure. VERY comfortable!

So if you are wondering what cup size to get, I went a size down from my normal size and it was perfect! I think a size up and everything would be looser and not hold me in as well.