Abstract: A system of monitoring impact stress, or acceleration forces on a user while exercising is disclosed. An exercise machine is equipped with sensing apparatus that measures the downward force exerted on the supporting surface by the lower extremities of the user. In this way, the corresponding impact forces are determined as a function of the user's body weight and communicated via a display monitor as “G-forces” or “Earth Gravity Units.” This allows the user to keep exercise impact within limits desired by the user, a physical therapist, or other qualified professional.

Abstract: A system of monitoring impact stress, or acceleration forces on a user while exercising is disclosed. An exercise machine is equipped with sensing apparatus that measures the downward force exerted on the supporting surface by the lower extremities of the user. In this way, the corresponding impact forces are determined as a function of the user's body weight and communicated via a display monitor as “G-forces” or “Earth Gravity Units.” This allows the user to keep exercise impact within limits desired by the user, a physical therapist, or other qualified professional.

Abstract: A pneumatically elevating recreational exercise device that utilizes in its preferred embodiment a commercially manufactured air cylinder (12) as an extendable air spring that is secured, or fixed to a horizontal surface or stand. A safety harness attachment (51) for securing a body harness is also provided. The device produces dramatic extension, or elevating capacity for vertical rebounding movement, and is entirely self-contained. An aspirating check-valve (10) is used to admit air at the top of the stroke, which produces added elevation with each vigorous leaping effort. This concept is also applied to an unsecured toy pogo stick embodiment.