Athletic on LetMeJizz
Plenty of these open on a treadmill, a yoga mat or a locker room before anything happens, the workout setting just an excuse to show off what the body can do. The performers are lean and trained, visible abs and hard glutes and the kind of flexibility that lets a scene fold into positions a softer body could not hold. That conditioning becomes the point once the fucking starts, stamina and balance on display as much as anyone's tits. Sweat reads as earned here rather than sprayed on.
160 athletic videos here, all HD and all free. New ones go up daily, so check back if you don't find your scene first time around.