Swim in place pool is a special type of pool, with powered water jet or water flow system on one end that creates an artificial current in the pool that keeps swimmers in place as they exercise. Some people refer to an exercise pool as an endless or infinite pool. If you are considering an exercise pool, these systems can be integrated into large or small pools and there are several systems based on your level of swimming abilities.
An exercise pool is great for people who are recuperating from a debilitating illness or injury. The jets can be set at different speeds, so the difficulty of the exercise increases along with the swimmer's ability. For a professional swimmer, a swim spa or swim in place pool allows them to stick to a rigorous workout routine.
There are several systems that create these currents some of which do not effect the aesthetics of the pool at all. A current system moves a large amount of water at a low pressure. These systems are generally the best from the swimmers stand point in that it feels the most like a real current. There are also swim jets which move smaller amounts of water but at much higher pressure and concentrated flow. The down side of these jets is that the flow tends to be turbulent and less enjoyable to swim in.