Workout

Warm up (600)
2 rounds
200 free/100 kick

Set (600)
3 rounds  
2 x 50 build on :50
100 free on 1:30
...descend 1-3 by rounds

Set (2100)
300 on 4:30
4 x 150 on 2:00
300 on 4:30
4 x 100 on 1:20
300 on 4:30
4 x 50 on :40

Cool-down (200)
200 easy