Water resistance lower body reciprocating exerciser

A lower body reciprocating exerciser, comprising:

• a frame having two posts on two sides thereof;
• two transmission units each having a cam which is a disk cam, a guide slot defined in a first face of the cam and a passive member located in the guide slot, the passive member connected with a first end of a piston rod, a piston connected to a second end of the piston rod, a shaft extending through the cam and connected to the post corresponding thereto;
• two resistance units connected to the two transmission units respectively, each of the resistance units having a cylinder which has a space defined therein, the piston and the piston rod located in the space of the cylinder corresponding thereto, the piston dividing the space into a top room and a bottom room, an enclosed loop pipe connected to outside of each of the cylinders, a top pipe connected between a top portion of the loop pipe and the top room of the cylinder, a bottom pipe connected between a lower portion of the loop pipe and the bottom room of the cylinder, the loop pipe having a down-flow section and an up-flow section, each of the down-flow section and the up-flow section having a check valve and an adjustable control valve, the check valve in the down-flow section and the check valve in the up-flow section being installed in opposite directions, water being filled in the space of the cylinder, and
• two swing units each having a pedal and an arm, the pedal connected to a lower end of the arm, a top end of the arm pivotably connected to a first end of the shaft of the transmission unit at the post corresponding thereto.