An article of footwear, comprising: an upper; and a sole structure engaged with the upper, wherein the sole structure includes: a polymeric foam member for supporting an entire plantar surface of a wearer's foot, wherein the polymeric foam member includes a foam material having a density of less than 0.25 g/cm 3, and a protective member engaged with the polymeric foam member to cover at least 60% of a surface area of a bottom surface of the polymeric foam member, wherein the protective member constitutes a web base surface with a plurality of traction elements extending downward from the web base surface, wherein a thickness of a majority of the web base surface at locations between the plurality of traction elements is less than 3 mm thick, and wherein the bottom surface of the polymeric foam member includes only four bulbous areas: (a) a first bulbous area extending outward from a base level of the bottom surface of the polymeric foam member at a rear heel area of the polymeric foam member, (b) a second bulbous area extending outward from the base level of the bottom surface of the polymeric foam member under a fifth metatarsal head support area on a lateral side of the polymeric foam member, (c) a third bulbous area extending outward from the base level of the bottom surface of the polymeric foam member at a medial side located under a first metatarsal head support area of the polymeric foam member, wherein the third bulbous area is centered forward and medial with respect to a center of the second bulbous area, and (d) a fourth bulbous area extending outward from the base level of the bottom surface of the polymeric foam member, wherein the fourth bulbous area is located forward of the third bulbous area and at a medial side located under a big toe support area of the polymeric foam member. an upper; and a sole structure engaged with the upper, wherein the sole structure includes: a polymeric foam member for supporting an entire plantar surface of a wearer's foot, wherein the polymeric foam member includes a foam material having a density of less than 0.25 g/cm 3, and a protective member engaged with the polymeric foam member to cover at least 60% of a surface area of a bottom surface of the polymeric foam member, wherein the protective member constitutes a web base surface with a plurality of traction elements extending downward from the web base surface, wherein a thickness of a majority of the web base surface at locations between the plurality of traction elements is less than 3 mm thick, and a polymeric foam member for supporting an entire plantar surface of a wearer's foot, wherein the polymeric foam member includes a foam material having a density of less than 0.25 g/cm 3, and a protective member engaged with the polymeric foam member to cover at least 60% of a surface area of a bottom surface of the polymeric foam member, wherein the protective member constitutes a web base surface with a plurality of traction elements extending downward from the web base surface, wherein a thickness of a majority of the web base surface at locations between the plurality of traction elements is less than 3 mm thick, and wherein the bottom surface of the polymeric foam member includes only four bulbous areas: (a) a first bulbous area extending outward from a base level of the bottom surface of the polymeric foam member at a rear heel area of the polymeric foam member, (b) a second bulbous area extending outward from the base level of the bottom surface of the polymeric foam member under a fifth metatarsal head support area on a lateral side of the polymeric foam member, (c) a third bulbous area extending outward from the base level of the bottom surface of the polymeric foam member at a medial side located under a first metatarsal head support area of the polymeric foam member, wherein the third bulbous area is centered forward and medial with respect to a center of the second bulbous area, and (d) a fourth bulbous area extending outward from the base level of the bottom surface of the polymeric foam member, wherein the fourth bulbous area is located forward of the third bulbous area and at a medial side located under a big toe support area of the polymeric foam member. (a) a first bulbous area extending outward from a base level of the bottom surface of the polymeric foam member at a rear heel area of the polymeric foam member, (b) a second bulbous area extending outward from the base level of the bottom surface of the polymeric foam member under a fifth metatarsal head support area on a lateral side of the polymeric foam member, (c) a third bulbous area extending outward from the base level of the bottom surface of the polymeric foam member at a medial side located under a first metatarsal head support area of the polymeric foam member, wherein the third bulbous area is centered forward and medial with respect to a center of the second bulbous area, and (d) a fourth bulbous area extending outward from the base level of the bottom surface of the polymeric foam member, wherein the fourth bulbous area is located forward of the third bulbous area and at a medial side located under a big toe support area of the polymeric foam member.