Yes, it's the off-season but you can still get in the pool. Try this unique workout from coach Sara McLarty.

A:

300 swim/300 pull/300 drill/300 kick
4×200 pull @ 3:00 (3/5/3/7 breathing pattern by 50)
8×25 @ :30 (1/2 FAST!, 1/2 easy)
20×100 @ 1:50 (75 RACE!/ 25 easy)
200 cool-down

*4400 total*

B:

300 swim/300 pull/300 drill/300 kick
3×200 pull @ 4:00 (3/5/3/7 breathing pattern by 50)
8×25 @ :40 (1/2 FAST!, 1/2 easy)
15×100 @ 2:30 (75 RACE!/ 25 easy)
200 cool-down

*3700 total*

C:

200 swim/200 pull/200 drill/200 kick
3×150 pull w/ :30 rest (3/5/3 breathing pattern by 50)
6×25 w/ :15 rest (1/2 FAST!, 1/2 easy)
10×100 w/ :30 rest (75 RACE!/ 25 easy)
100 cool-down

*2500 total*