noun - Descending sets are training interval sets performed in a swimming pool or an open body of water where the swimmer or triathlete swims each repetition faster than the previous repetition. For example, in a set of 6 x 50 descend 1-6, the swimmer will swim six 50's with each 50 gradually getting faster. If the set is six swims around a turn buoy descend 1-3, 4-6, the swimmer will swim gradually faster on the first three buoy swims and then slow up on the fourth buoy swim and then gradually get faster until the sixth buoy swim. Th interval generally stays the same, giving the athlete more rest as their swimming time descends (gets faster).
The swimmers were given a descending set of 6 x 200 on a tough interval.