A midsole (10 and 22) for an activewear shoe (12) comprises a removable insert (10) and a peripheral member (22). The peripheral member (22) is joined to the perimeter of an upper surface (18) of an outsole (14). A reinforcing layer (28) substantially less thick than the peripheral member (22) is joined to the outsole upper surface (18). A transverse reinforcing segment (30) is integrally formed with the peripheral member (22) to provide stability and support to a wearer of the shoe (12). Segment (30) forms a front receptacle (32) and a heel receptacle (34) dimensioned to receive insert (10). Insert (10) has a transverse slot (42) to match with the transverse segment (30). A plurality of independent cushioning elements (40) depend from a base member (38) of insert (10), and are sized in order to conform to the depth of peripheral member (22). The cushionability and resiliency of insert (10) may be selected according to the wearer's weight and cushionability preference.