noun - A progressive descend set is a long swimming set done by competitive pool and open water swimmers. The set consists of a number of swims where every subsequent swim or set of sets is done at an increasingly faster pace.
The progressive descend set includes 3 x 1000, 3 x 800, 3 x 600, 3, x 400, and 3 x 200.
Progressive Prime Number Descend
A Progressive Prime Number Descend is a swimming set done by competitive pool and open water swimmers, based on prime numbers without a pattern: 2 x 175 @ 3:23 + 3 x 175 @ 4:15 + 5 x 175 @ 6:14 + 7 x 175 @9:13.