Workout

Warm-up (900)
300 swim, 100 kick
200 swim, 100 kick
100 swim, 100 kick

Set (200)
4 x 50 build on :50

Set (600)
3 x 200 IM
...#1 drill @ 3:40
...#2 build each stroke @ 3:30
...#3 hard

Set (500)
4 x 100 on 1:30 (descend #1-3, #4-6)
100 easy on 2:00

Set (600)
12 x 50 on 1:00 IM switch
a. fly
b. fly/bk
c. bk
d. bk/br
e. br
f. br/fr

Cool-down (200)
200 easy