Soft swimsuit style material - the breastfeeding clips and access are ideal for feeding. In terms of hold I have done a “bootcamp” style class and a Pilates class which this worked well for. I probably wouldn’t go for a long run (but as 32H before breastfeeding I think this is a lot to ask of one sports bra support level). I did buy M but with the extender provided think I will size down for next one. It is a little tricky to get on but very comfy once on.