Abstract: A kit includes a first article of footwear and a second article of footwear. The first article of footwear includes a first upper, a first sole structure having a first outsole defining a first ground-contacting surface, and a first side support extending between and connecting the first upper and the first outsole at a medial side of the first article of footwear. The second article of footwear including a second upper, a second sole structure having a second outsole defining a second ground-contacting surface, and a second side support extending between and connecting the second upper and the second outsole at a lateral side of the second article of footwear. In one aspect, the first sole structure includes a first fluid-filled chamber and the second sole structure includes a second fluid-filled chamber, wherein the first fluid-filled chamber is identical to the second fluid-filled chamber.