Abstract: The present invention includes a treadmill system including a support platform, a liquid tank, and a lift support structure connected to a treadmill assembly by a lifting mechanism. In general, the liquid tank and the lift, support structure including the treadmill assembly move horizontally relative to and independent of one another along the support platform to position the lift support structure away from or about the liquid tank. In addition, the treadmill assembly moves vertically relative to and independent of the lift support structure using the lifting mechanism to lower or raise the treadmill assembly within an interior of the liquid tank or exterior of the liquid tank. More importantly, the combination of the horizontal movement and the vertical movement of the treadmill assembly permits a mammal to step onto the treadmill assembly before the treadmill assembly is raised and then lowered into an interior of the liquid tank.