Workout

Warm up (800):
2 x 200 (75 free/25 non-free)
4 x 50 dolphin kick on back on 1:00
2 x 100 free on 1:30

Main set (1600):
2 rounds
200 on 4:00
…50 back drill/50 free  
2 x 100 on 1:45
…25 free/25 back
200 back on 3:30  
2 x 100 on 1:30
…75 free/25 back

Set (500)
500 pull
…moderate

Cool-down
200 moderate
100 EZ