Workout

Warm-up (600)
300 swim, 100 kick  
200 drill

Set (600)
12 x 50 on :50
…odds: DPS                              
…evens: descend 1-3  

Set (1800)
400 pull 6:00                                            
2 x 200 on 2:45
…build and descend  
400 steady 5:30
12 x 50 pace on :40 

Set (300)
Kick 6 x 50's on 1:00
...25 under/25 fast

Cool-down (200)
200 EZ