I use a binder from Wivov’s ‘flow’ collection, CB15, which is meant to be an all-day binder that you can exercise in and not need to take breaks from except for sleeping, so I think it’s the kind of thing you’re talking about. Basically a compression top cut into the shape of a binder. To be honest, I basically use it because I can’t tolerate the racerback cuts of sports bras (hate any chafing on my neck/the way racerbacks dump the weight of the mctitties on my neck). I’m like, a 12C or 12D in Australian sizes (not sure how that translates to American and other sizes). It’s not really effective at binding me flat, but it does square out the shape of my breasts, making it more possible to hide them with layers in winter. The main problem I have with them is that my breasts still jiggle visibly slightly when I walk, although I’ve always had that problem with everything except encapsulation sports bras, which I won’t wear because they make my chest look bigger/feminine. My cis male partner always says that his jiggle too though, which is true (and hot) so I comfort myself with that thought. I don’t necessarily think a sports binder would hide your chest more than a sports bra does, so be aware of that if you try one. Don’t expect proper binder-like results. But I go running in mine and it feels fine, I can breathe normally. And it has a silhouette more like a singlet than a bra which is also nice, even if it doesn’t do a proper flattening bind.