Workout

Warm Up (600)
Swim 12 x 50's on :50

Set (600)
4 x 150 on 2:15
...50 free, 50 stroke, 50 free

Set (1000)
2 Rounds:  
3 x 100 build on 1:30
4 x 50's on :45
…descend 1-4
 
Set   
Timed-20 mins. Swim
..build/hold steady pace
 

Cool-down (200)
200 EZ choice