Abstract: An exercising device employing the principle of isotonic exercise in conjunction with isometric exercise to improve and develop the muscular and bone structure of various parts of the human body. In two embodiments of the invention, the apparatus includes a first class lever which is pivotably mounted on a supporting structure in a manner which permits the lever to operate against a force resisting spring. The spring is capable of sudden disengagement from the lever thereby permitting the lever to travel freely under the influence of the applied operator force. The travel of the lever is positively impeded by a striking block which imparts an impact to the operator through the lever. In a third embodiment, the apparatus includes a biforcated third class lever having a spring mounted between the frame and the lever.