Workout

Warm-up (400)
300 swim
100 kick

Set (300)
8 x 50's choice …rest10 sec.

Set (2400)
2 rounds  (descend 1-5, or 1-4)
12 x 100's on 1:40
Or 
10 on 1:45
Or
8 on 2:00
Or
6 on 2:15
…..rest 2 mintues between rounds

Cool-down (200)
200 moderate to EZ choice