Workout

Warm-up (500)
200 Swim, 100 Stroke
200 Kick 

Set (600)
12 x 50 drill on 1:00
...3 each stroke 

Set (1600)
4 rounds
125 on 2:00  75%
100 on 1:30 80%
75 on 1:00 90%
50 on :30 all out! 
50 EZ on 2:00 

Cool Down (300)
100 kick
200 choice
...moderate to EZ