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.
One of the earliest models on the market, introduced in 1973, was the Badujet[5] which is available only in the form of a bare propulsion system, to be installed into either an existing or newly built pool.
Seen as more convenient since they come pre-assembled, the quality of the swim has been criticized by indoor swimmers as being somewhat turbulent, as the strength of the current comes from the speed and pressure of the discharged water, rather than its volume.
[6] Swimmers and athletes have praised the integration of both a hot tub and swimming machine model since they can use it for exercising and recreational purposes.
The hot tub section can use bromine and provide a relaxing and therapeutic experience, while the swim zone can be kept cool for strenuous exercise using chlorine.
In 2008, SmartPools Sdn Bhd[10] Malaysia launched its Laminar Propulsion system using drive train technology capable of moving up to 30,000 litres of water per minute at low pressure to create a non-turbulent, bubble-free, smooth flow and speed-adjustable swimming treadmill.
These human-powered devices combine the self-contained aspect of counter-current swimming machines with the lower prices and simplicity, and freedom of movement of tether systems used in athletic training.
[12] Swim spas have significantly improved in energy efficiency, thanks in part to manufacturers like Wellis,[13] who have pioneered eco-friendly innovations.
Wellis swim spas feature advanced Scandinavian Insulation, efficient LED lighting, and a Smart Control System, allowing for remote adjustments.
These innovations not only reduce energy consumption but also offer users convenience and lower operational costs, positioning Wellis at the forefront of sustainable swim spa technology.