A cutout back does two things at once: it opens the shoulder blades for airflow where heat builds fastest, and it gives the bra a finished look worth wearing on its own in a studio.
The padding is removable-style molded cup construction, giving shape and coverage without a separate insert to shift out of place mid-workout. Support holds through inversions and overhead movement rather than riding up when you go upside down.
The fit is snug enough for running and secure enough for yoga, which is a harder combination than it sounds — most bras do one well and the other poorly. Suited to yoga, training, running, or wearing under an open layer.