An article of footwear comprising: an upper including a side portion that has a first material composition at an exterior surface of the side portion; and a sole structure secured to the upper and having a side wall, the side wall having an exterior surface that directly underlies the exterior surface of the side portion of the upper, the sole structure having a second material composition at the exterior surface of the side wall, the second material composition being different from the first material composition of the upper; the upper has a forefoot region that includes a toe box region and a vamp region contiguous with the toe box region; the toe box region is adjacent to the sole structure and between the sole structure and the vamp region; the toe box region has a first thickness; the vamp region has a second thickness less than the first thickness; the upper includes an outer unit that has a forefoot region, a midfoot region, a heel region and the side portion with the exterior surface; and the outer unit is a one-piece, unitary component, wherein the outer unit of the upper includes an outer layer and an inner layer, the outer layer including the side portion with the exterior surface; the exterior surface of the side portion is in the toe box region; and the exterior surface of the side portion is contiguous with an exterior surface of the vamp region; wherein the article of footwear further comprises: tensioning cables secured to the sole structure and disposed between the outer unit and an inner unit disposed inward of the outer unit and defining a foot-receiving cavity; wherein the outer unit has eyelet openings; and wherein the tensioning cables form loops remote from the sole structure and configured to be disposed adjacent to the eyelet openings. an upper including a side portion that has a first material composition at an exterior surface of the side portion; and a sole structure secured to the upper and having a side wall, the side wall having an exterior surface that directly underlies the exterior surface of the side portion of the upper, the sole structure having a second material composition at the exterior surface of the side wall, the second material composition being different from the first material composition of the upper; the upper has a forefoot region that includes a toe box region and a vamp region contiguous with the toe box region; the toe box region is adjacent to the sole structure and between the sole structure and the vamp region; the toe box region has a first thickness; the vamp region has a second thickness less than the first thickness; the upper includes an outer unit that has a forefoot region, a midfoot region, a heel region and the side portion with the exterior surface; and the outer unit is a one-piece, unitary component, wherein the outer unit of the upper includes an outer layer and an inner layer, the outer layer including the side portion with the exterior surface; the exterior surface of the side portion is in the toe box region; and the exterior surface of the side portion is contiguous with an exterior surface of the vamp region; wherein the article of footwear further comprises: tensioning cables secured to the sole structure and disposed between the outer unit and an inner unit disposed inward of the outer unit and defining a foot-receiving cavity; wherein the outer unit has eyelet openings; and wherein the tensioning cables form loops remote from the sole structure and configured to be disposed adjacent to the eyelet openings. tensioning cables secured to the sole structure and disposed between the outer unit and an inner unit disposed inward of the outer unit and defining a foot-receiving cavity; wherein the outer unit has eyelet openings; and wherein the tensioning cables form loops remote from the sole structure and configured to be disposed adjacent to the eyelet openings.