Behind the Design of Faith Kipyegon’s Breaking4 Speed Kit

A legendary runner. A legendary goal. Faith Kipyegon is one of the most accomplished middle-distance runners in history. To push herself beyond simply earning more gold hardware, she set her sights on breaking a barrier thought to be indomitable — running a sub-4-minute mile. To match that goal, Nike is bringing its full power of sports science research and design expertise to create the integrated made-for-speed products to help get her there: a first-of-its kind speed suit, a sports bra made of a revolutionary 3D-printed performance material, and a featherweight spike that turns the dial on innovative features up to 11.

The Nike team knows that performance in the mile is decided by the sum of many fractional decisions. The choice to hug the inside rail or float to the outside. Sprinting a breakneck pace at the start or hanging back to assess the field.

Designing for an audacious attempt like Breaking4 is similar. Functionally, all of the Nike products need to combine, piece by piece, to help Kipyegon — the women’s current world record holder in the mile at 4:07.64 — shave off the 7.65 seconds she needs to meet her goal.

“The integrative nature of this kit means everything with this attempt,” says Brett Kirby, Principal Researcher in the Nike Sport Research Lab (NSRL). “Not any one thing will help her break it.”

Here, Nike researchers and scientists unpack the power of the three Breaking4 innovations.

To fight these forces, enter the Nike Fly Suit, a one-piece apparel solution with a complementary headband and arm and leg sleeves featuring sleek, stretchy materials designed to help Kipyegon stay “slippery” to move through the air as efficiently as possible. The material used on the headband, arm sleeves and leg sleeves is lighter than that on the suit, which covers Kipyegon from below the neck to just about the knee. As apparel gets further away from the body’s center of gravity, keeping it lightweight becomes even more important to help Kipyegon conserve her energy. Plus, aerodynamic materials perform differently depending on their location across the body.

Nike’s star innovation feature in mitigating air forces are the Nike Aeronodes. These half spheres vary in size; some are smaller than a pencil tip. The Aeronodes are strategically placed on the suit to accomplish two goals: split the air in front of Kipyegon and create smaller eddies behind her to reduce drag.

Put another way, the job of the Aeronodes is to keep the wind “attached” to Kipyegon, or streamlined to her body, says Lisa Gibson, Senior Project Manager for Apparel Innovation. Without them, the wind whipping behind Kipyegon gets “noisy and nasty.” Picture a rock in the middle of a rushing river, water wrapping tightly around the rock’s mass. Now, imagine if the wake of the current behind the rock wasn’t pulled back in, but instead radiated further and further away from the rock, those swirling eddies increasing in intensity. That’s what happens when running at Faith’s speed in a typical suit. The Nike Fly Suit’s Aeronodes help the wind act like that rushing water around the rock, pulling the air tighter against her body and creating the smaller eddies behind her.

Adding elements to make the suit faster might seem counterintuitive. But the project’s goal — to combine incremental product changes to give Kipyegon the best chance of breaking 4 minutes — required Nike scientists and researchers to suspend preconceived notions.

“On our innovation team, we always start by challenging any assumptions we have about athlete performance,” says Gibson. “We know our legacy with footwear design and the importance of the spike in cutting down runner times. But when we continued to explore the advantage we could gain from the apparel Faith wears — a conversation that we helped lead with Eliud Kipchoge and Breaking2 — it became clear how much faster Faith could potentially run if the suit had certain physical features beyond the slickness of its material.”

The proof was in the testing, beginning with a digital wind simulation. Here, the team interrogated every detail of how the Aeronodes showed up — each one’s circumference, height, the spacing between them. Digital simulations allowed the team to test a range of configurations in a short amount of time without needing to create physical nodes on the suit. As the configurations looked more promising, the testing moved into a wind tunnel; then onto the track; and finally, most important, to Kenya for Kipyegon to try herself.

“We could say that a product feature might help make Faith faster,” says Amy Jones Vaterlaus, VP Innovation, NSRL. “But if that product feature doesn’t match how Faith likes to feel, move and show up, then we’re not doing our jobs. The balance between the benefits of the speed suit and its familiarity for Faith was crucial.”

“This 3D-printed material innovation represents something entirely new on a visual and visceral level,” says Janett Nichol, VP, Nike Apparel Innovation. “Sports bras have never looked or felt like this before. The material is soft, light and incredibly supportive — yet it also feels like you’re not wearing anything at all. We know Faith’s bringing everything she has to achieve this goal, so we knew Nike FlyWeb had to be part of our contribution.”

The footwear team explored dozens of options, the models ranging from subtly different to net new. Kipyegon’s preferences guided the final verdict. The team leveled up a new silhouette made to Kipyegon’s specifications — the Nike Victory Elite FK — that is light, propulsive and, most important, fast.

“Track spikes are incredibly important for preserving energy while running,” says Carrie Dimoff, Footwear Product Director, Nike Innovation. “The suit addresses the energy demand to run through air. Faith’s spike features completely new components designed to increase her energy return and improve her running efficiency. The spike is also significantly lighter than anything she’s worn before. We’re storied in our spike design history at Nike, and still, we’ve pushed even further into the future with Faith’s Victory Elite FK spike.”