Workout

Warm-up (300) 6 mins
300 swim

Set (300)
6 x 50 on (1:10/1:00/:50) 
...10 sec. kick on wall, swim

Set (1600)
4 rounds
4 x 100's  
1:25/1:35
1:45/2:00
...25 sprint/50 long strokes /25 sprint
 
Set (500)
3 x 50 on :55, breat control
2 x 50 on 1:00, kick
1 x 50 sprint on 1:00
2 x 50 on 1:00, kick
3 x 50 on :55, breath control

Cool-down (100)
100 easy