Workout

Warm-up (600)
400 swim
200 pull (buoy only)
...3,5,7,5 cb by 50's

Set (600)
6 x 100's on 1:30
...odd IM
...even EZ free

Set (600)
Pull 300, 200, 100
...3,5,3 cb 
...rest 10
 
Set (1000)
Swim 2 x 500
…build each 100 
...keep HR 140-150
…descend 1-2

Set (300)
Swim 6 x 50 choice
...AS FAST AS POSSIBLE

Cool-down (400)
...swim 200 moderate
...EZ 200