Workout

Warm-up (500)
300 swim
200 kick

Set (600)
Pull 4 x 150's on 2:15

Set (400)
8 x 50's on 1:00
...drill swim
...IM order

Set (800) 
4 x 100's on 1:30
4 x 50's kick on 1:15
4 x 50's free on 1:15
...fast (add up time for a 200)

Set (600)
Pull 400
...neg split
4 x 50's build on 1:00

Cool-down (200)
200 EZ swim