Ah, a topic close to my heart
I usually wear a crop top cycling, but after seeing pics of myself at the last TT, I decided I looked very saggy (more than normal) so think I will 'bra up' for riding in future.
I use a berli sports bra for running, underwire - need it for support - and with lots of breathable fabric. Trouble is it has seams so looks ghastly under a thin coolmax top. The smooth ones don't have enough support. If I try wearing a crop top over it, I can't breathe. Maybe ! need a crop top 2 sizes too big and then I could breathe!
Seems no matter what size we are - we all have issues! (think I'm a 36C - but shrinking, cos I'm losing weight)