Swimming: Triathlete's Main Set

Here's a good main set that you can do one of two ways. You can either work the distance part of the set at a hard pace, and use the 100's as a moderate recovery, or you can swim the longer distance portions at a fast-distance pace and push the 100's, trying for a lower overall split in the 100's than you had in the longer distance.

I swam this last night, choosing to work the distance portions, keeping a 1:20 pace going, and then swimming the 100s at a 1:25 pace.

400, 4 x 100
300, 3 x 100
200, 2 x 100
100 100

Total: 2,000 yard main set. If you want to do it differently on another day, reverse the order and swim it with the 100's first and the 400 last.