Workout

Warm-up (500)
400 swim
…50 free/50 drill
100 kick

Set (900)
3 rounds
3 x 50 as follows:
  1) 25fl/25fr on :50
  2) 25bk/25fr on :55
  3) 50br/50fr on 1:00
1 x 150 on 2:15
...EZ/MED/HARD
 
Set (1500)
2x100 (1 EZ/1 fast)
2x100 best pace

2x100 (1 EZ/1 fast)
2 x 75 best pace

2x100 (1 EZ/1 fast)
3 x 50 best pace

2x100 (1 EZ/1 fast)
8 x 25 best pace

Cool-down (100)
easy 100 warm down