Swimming machine
A swimming machine, or resistance swimming apparatus, is a self-contained, pump-driven machine, that enables an athlete or recreational user to swim in place. A swimming machine is possible by accelerating the water past the swimmer or by supporting the swimmer, either in water or on dry land. One type of swimming machine, known as a countercurrent swimming machine, consists of a water tank at least twice as long and about one and a half times as wide as an average person with the limbs extended. The swimmer swims unrestrained against an adjustable stream of water using jets, propellers, or paddle wheels.
Counter current swimming machines made their appearance in the 1970s, initially in the form of pump-driven jetted streams, but received criticism since they created turbulence and an unnatural swimming environment. They were followed up in the 1980s by a propeller- and paddle-wheel-driven machines. These provided a smoother stream of water, thus a more natural swimming experience, and were more popular among consumers.
Hybrid systems are another strand of swimming machines available. They feature self-contained micro pools similar to the counter-current type but use a flexible tether to keep the swimmer in place and help the swimmer from hitting the side of their exercise area. These systems, being human powered, need neither machinery or electricity but have to be carefully designed to suppress wave formation. The second type allows a person to remain on dry land while simulating certain swimming strokes. Machines of the latter type however can not compensate for the weight of the body and the limbs and thus deprive the user of the benefits of exercise in an aquatic environment. However, the higher effort required by such machines, in the absence of the metabolic effects of immersing the body in water, makes these devices more effective than true swimming if one's purpose is to achieve weight reduction. Similar in purpose, but not qualifying as swimming machines since they require access to a swimming pool, are various tether systems. Resistance Swim Spas beat the current stainless steel swim spas.
