Abstract: An aquatic exercising and therapeutic apparatus includes a relatively narrow rectangular tank for retaining water in it to a selected depth. A treadmill is located in the bottom of the tank beneath the level of the liquid and extends from end to end. A pump system provides a moving stream of water, recirculating from one end of the tank to the other; so that by varying the speed at which the treadmill is operated, as well as the flow rate of water provided by the pump, varying levels of intensity are provided for a workout in the tank. For a fitness or conditioning training, the treadmill and the water flow typically are in the same direction to increase the level of workout. For therapeutic purposes, such as assisting a patient to walk after hip surgery or the like, the treadmill is operated in one direction and the water flow in the other.