Made for short runs when you want a barefoot-like feel, the Nike Free RN Flyknit 2018 feels super light and flexible. Its sock-like upper has more stretch yarns than previous versions, so it hugs your feet more than ever. The innovative sole has an updated construction, yet still expands and contracts with every movement. The packable design makes the shoe easy to stuff into your bag—so you can get in a few miles on the fly.