to design a sports bra is to design for a constantly moving target. breasts rise and fall with every jump. run forward and they arc like a figure eight. “breast tissue movement goes in many ways,” says nicole rendone, a nike designer who spends most of her time engineering bras to mitigate those movements. “the number of components that go into a high-support bra is immense.”nike’s high-support bras can include upwards of 40 parts—things like supportive straps, elastic underbands, and stabilizers hidden in the exterior fabric panels—all designed to create stability without squishing what's inside. which is why nike’s newest sports bra, the fe/nom, seems like an architectural anomaly. the whole thing consists of two pieces of fabric stitched together. the secret? it's made from flyknit, the material best known for nike’s kicks.nikefirst introduced in 2012, flyknit combines weaves of various tightness to create fabric that's simultaneously flexible and sturdy. on nike's shoes, the weave is looser where the foot needs less support (near the toes) and tighter where it needs more (on the sides). the result is a fitted, unibody upper without extra stitching, and a shoe that feels more like a sock.the fe/nom uses the same technique. it’s not unibody—the front and back are stitched together—but the bra functions like a single piece of fabric with six differe...