Workout

Warm-up (500)
500 choice

Set (600)
4 x 150 on 2:20
...50 kick/100 swim  

Set(2100)
3 rounds
2 x 100 build on 1:30
2 x 50 moderate on :45
150 on 2:00 
... steady pace
200 on 3:00
...descend 200s by rounds
50 easy on 1:00

Cool-down (200)
200 EZ