Workout

Warm-up (600)
300, 200, 100 free 
...last 50 drill

Set (500)
5 x 100 pull on 1:30 
...3cb 

Set (1400)
400 free on 6:00 
2 x 50's on 1:00 specialty - 90% effort 
300 free on 4:30 
2 x 50's on 1:00 specialty - 90% effort 
200 free on 3:00 
2 x 50's on 1:00 specialty - 90% effort 
100 free on 1:30 
2 x 50's on 1:00 specialty - 90% effort 
...keep 4-3-2-1 aerobic but solid 

Set (500)
500 swim
...choice of equipment