Abstract: The invention is a leg muscle strengthening device used for warming up, exercising, and strengthening the muscles of the lower limbs particularly after a period of immobilization or in order to carry out particular sporting or artistic activities. The invention comprises a main body including, in use, at least one work portion and at least one portion of abutment on a support, the main body being composed of an elastically deformable material, and the work portion and the abutment portion being yieldingly maintained in a mutually angled arrangement.