A midsole (12 and 24) for an activewear shoe (10) comprises a removable insert (12) and a peripheral member (24). The peripheral member (24) is joined to the perimeter of an upper surface (20) of an outsole (16). A plurality of independent cushioning elements (40) depend from a base member (38) of insert (12), and are sized in order to conform to the depth of peripheral member (24). A window (14) is formed through the peripheral member (24) and/or the outsole (16) to allow observation of the insert (12) from exterior the shoe (10). To reinforce the peripheral member (24) proximate the window (14), a row of stiffened cushioning elements (62) is formed on the insert (12). The stiffened elements (62) have a higher durometer reading than the remaining elements (40) and are formed during an injection molding process. A transverse reinforcing segment (31) may be provided to inhibit movement of the insert (12) within the shoe (10). If desired, the segment (31) and the elements (40) may be formed with cavities therein to lighten the weight of the shoe (10).