Workout

Warm Up (500)
Swim 10 x 50's rest 5

Kick-set (400)
400 IM 

Set (1600)
200 swim drill 
5 x 100 free on 1:40
... (hold steady pace) 
200 moderate to EZ swim 
5 x 100 free on 1:35 
...(controlled harder pace) 
200 moderate to EZ swim 

Set (300)
6 x 50 choice on 1:30 
…odd-FAST
…even-moderate

Cool-down (200)
200 EZ