Workout

Warm-up (600)
3 x 200 r:20 sec
...last 50 stroke

Set (900)
6 x 150's on 2:45
...50 kick/100 swim
..descend 1-4

Set (1600)
4 rounds
4 x 100's
...extra 15sec  b/RDs
RD 1 
50 drill/50 swim on 1:30
RD2
50 DPS/50 FAST on 1:30
RD3
50 Build within RD on 1:30
RD 4
Best Average on 1:15

Cool-down (300)
100 kick
200 Swim