Twisting exerciser

A twisting exerciser comprising:

• a base having a frame, a first shaft, a second shaft and a stop member respectively connected to the frame;
• a first swingable unit having a first fan-shaped gear, a pad and a connection bar, the first fan-shaped gear having a first sleeve which is pivotably mounted to the first shaft, the stop member limiting a swinging angle of the first fan-shaped gear, the pad secured to a top of the first sleeve, the connection bar having a first end fixed to the first sleeve, an extension section extending upward from a second end of the connection bar, a rod transversely connected to the extension section and located higher than the pad, and
• a second swingable unit having a second fan-shaped gear and a handle assembly, the second fan-shaped gear having a second sleeve which is pivotably mounted to the second shaft, the first and second fan-shaped gears being engaged with each other, the handle assembly having a transverse bar, a head tube and a handle, the transverse bar having a first end thereof connected to the second sleeve, and a second end of the transverse bar connected to a lower end of the head tube, the handle having a collapsible tube extending from a center thereof, the collapsible tube retractably connected to a top end of the head tube, the handle assembly including a bolt and a resilient unit, the second end of the transverse bar having a pivotable part which has a threaded hole, the lower end of the head tube pivotably connected to the pivotable part and having two bores defined through a wall thereof, the bolt extending through the bores and threadedly connected to the threaded hole of the pivotable part to secure the head tube relative to the second end of the transverse bar, the resilient unit connected between the lower end of the head tube and the pivotable part, when the bolt is removed from the lower end of the head tube and the pivotable part, the head tube is pivotable relative to the second end of the transverse bar, the resilient unit provides a force to return the head tube, the pivotable part including an elongate hole, the resilient unit including a pivot, a second bolt, a nut and a spring, the pivot rotatable connected to the lower end of the head tube, the second bolt of the resilient unit extending through the pivot and the elongate hole, the nut connected to an end of the second bolt of the resilient unit, the spring mounted to the second bolt of the resilient unit, the spring biased between the nut and the pivotable part.