This was my swim workout for today. I enjoyed it, thought I'd share it for those who need help coming up with workouts. I tried to strike a balance between endurance and speed, so I have some long repeats, with speed work at the end.
6x300 @ 6:30
6x50 @ 90%, 20 sec RI
100 EZ cool down
The main set is fairly small (2100), but if you need something longer, you can always add more repeats. Also, choose a sensible interval; if 6:30 is too slow for you, cut it down; if it's too fast, don't kill yourself. You want your heart rate to be up for the 300's, but you don't want to be near your lactate threshold.
Notes (for those who don't understand swim workout lingo): SPK means 200 yds swimming, 200 yds kicking, and 200 yds pulling. 6:30 refers to the interval on which you start your 300's. If I start my first 300 at 5:30 on the clock, I need to leave for the next one at 12:00. So if I swim the 300 in 6 minutes, I get 30 seconds to rest before the next set. Some drills I like to do are bi-lateral breathing, fist swimming, and one-arm pulling. The 90% can refer either to heart rate (as a percentage of your lactate threshold) or perceived effort. RI is rest interval, so you should rest for 20 seconds between 50's.
Also, you shouldn't do this workout until you have a solid aerobic base built up. Which means if you're just getting started with training, you should take a good three weeks to do long, slow swims before you get into speedwork.
If you have any questions about the workout, or need tips on how to build a swim workout, leave a comment.