Abstract: A midsole for athletic shoes, especially for medium and long distance track events, of soft elastic material, which in the heel area has, on its underside, a recess into which is inserted a stabilizing element of a material that is harder than that of the midsole is improved so that harmful supination positions are avoided. This is achieved by the fact that the stabilizing element (9) consists of a U-shaped part (10), covering the entire heel edge area, and a part which closes the U-shaped part at the middle part of the foot in a manner creating a window (13) into which an island of the full thickness of the midsole engages. The stabilizing element (9) also has a strip which extends along the lateral side of the midsole up to at least, approximately, the little toe area of a shoe provided with such a midsole.