Abstract: The present invention is dedicated to a calf exerciser including a foot unit having foot-palm and heel support surfaces. The foot unit provides efficient resistance training of calf muscles by permitting both eversion or inversion movements of the foot-palm in synchronization with the plantar flexion dorsiflexion muscular contraction. This is achieved by inclining the foot-palm support surface either towards the exterior or the interior sides of the foot unit, by anteo-posteriolly curving the heel support surface from the foot-palm surface to the bottom of the foot unit and by including a gradual inclination of the heel support surface towards the exterior or the interior sides of the foot unit, thus forming a variable angulation foot sole gradient area. This variable angulation foot sole gradient area accentuates the eversion and inversion movements at the foot-palm and reduces the biomechanical stress by eliminating coronal rotation at the heel.