Workout

Warm-up (500)
10 x 50's on :55
...build

Set (400)
4 x 100 on 1:45
...25 build/25 fast

Set (1500)
3 rounds
100 HARD
100 EZ
50 HARD
50 EZ
100 HARD
100 EZ

Set (400)
Kick 8 x 50's 
...25 under/25 BLAST

Cool-down (200)
200 EZ choice