Abstract: Disclosed is an exercise device including a piston disposed within a cylinder having a first open end and a second end having a valve which independently controls air intake and exhaust through the second end of the cylinder, thereby controlling the air pressure exerted on the piston and hence the force required to raise the piston. A flexible connector is attached to the top of the piston, exits through the open end of the cylinder, and passes through a series of pulleys such that force exerted by the user on the opposite end of the connector is transmitted to the piston, whereby the piston slides within the cylinder.