an exercise staff is comprised of two half staffs which can be coupled together . each half staff includes a handle portion and a base portion , connected by a spring . an inner cylinder connected to the handle portion has an l - shaped groove with an axial segment . a pin in the base portion engages the groove and when the pin is in the axial portion of the groove , the handle and base portions may be separated with resistance by the spring . the handle portion is adapted to receive inserts of varying weights to modify the mass of the staff in use .