Purchased alongside matching leggings. I debated between XS and S because I’m a size 6-8 but I feel sport bras can often run small so I went for the small and thankfully I did. I would say it is actually still a tad snug around the band, but sits nice once on. Not a lot of stretch. Would say it offers medium support at best, if you are bigger in this region I suspect it won’t offer much support for you. I don’t think it would be suitable for cardio, I will use mostly for weight training or yoga.  I would recommend going a size up. 

Love this sports bra. I bought it in a medium and would normally be a size 10. I found the band at the bottom a little tight but was worried it mightnt be supportive enough as it was slightly looser at the top but when training and running I found it brilliant