Workout

Warm-up (700)
400 swim 
300 kick 

Pull-set (600)
3 x 100 on 1:40 (50 drill/50 swim) 
300 pull (5cb) 

Set (400)
400 IM swim - fins ok
...50 swim/50 drill 

Main-set (1200)
16 x 75 free (hold pace) on 1:10
...descend 1-4  

Warm-down (300)
200 moderate choice 
100 EZ kick