Abstract: A resistance device for a physical exerciser includes a cylindrical housing formed with two diagonally opposite chambers at two opposite sides thereof, a fastener fixedly mounted on an inner side thereof, and a groove formed on an inner side thereof and arranged under the fastener, a pair of actuating rods inserted into a respective one of the chambers and provided with a hook and connected with a spring by a pin, an upper end of the spring being connected with the fastener, a pair of buttons pivotally connected with a top of the cylindrical housing, a tubular axle fitted within the cylindrical housing and provided with a first set of teeth and a second set of teeth which are positioned together beside each other and operate in opposite circular direction, an axle formed with a spiral groove extending through an outer surface thereof, a core member fitted within the tubular axle and having a radial hole aligned with the spiral groove, a pin inserted through the spiral groove so that a lower portion of the pin