Young Brunette Girl Posing At The Swimming Pool

A pool may be referred to as fast or slow, depending on its physical layout. Some design considerations allow the reduction of swimming resistance making the pool faster: namely, proper pool depth, elimination of currents, increased lane width, energy absorbing racing lane lines and gutters, and the use of other innovative hydraulic, acoustic and illumination designs.
Exercise pools
In the last two decades, a new style of pool has gained popularity. These consist of a small vessel (usually about 2.5 m x 5 m) in which the swimmer swims in place, either against the push of an artificially generated water current or against the pull of restraining devices. These pools have several names, such as swim spas, swimming machines, or swim systems. They are all examples of different modes of resistance swimming.