Workout

Warm-up (600)
300 swim
200 kick
100 swim

Set (300)
6 x 50s on 1:00
Odds: 25 underwater w/5 sprint strokes then 25 easy  
Evens: 25 drill/25 swim 

Set (300)
6 x 50s free: start at 1:00
...descend interval by :05
 
Set (1600)
4 rounds
4 x 50 choice stroke descend on :50/:55/1:00/1:10
150 free FAST on 2:15 
50 EZ on 1:00
 
Set (300)
3 x 100 pull w/ 10 sec. rest 
... breathe by 50's,3/5, 5/7, 7/9 

Cool-down (200)
200 EZ