Workout

Warm-up (300)
300 swim
...free/back
 
Set (500)
10 x 50 build on :50
…4 cb

Set (1900)
4 x 200 on 3:00 
…build by 50
4 x 150 on 2:30
4 x 100 on 1:30 
…descend 1-2
2 x 50 on 1:30 
…FAST!

Cool-down (100)
100 easy