Sitting beneath the rectus femoris, the vastus intermedius is one of the four muscles which compose the quadriceps.
Like the other quadriceps muscles, the vastus intermedius is successfully exercised with squats and leg extensions. Other exercises which incorporate the extension of the knee will equally recruit the muscle, such as cleans and snatches.
Being deeper within the quadriceps structure, the vastus intermedius can prove more difficult from a therapeutic stand point. Tissue manipulation, releasing, and stretching are more challenging for the muscle compared to the other, more superficial, quadriceps muscles.