Just keep swimming, swimming, swimming.
Lately, though, this little motto of mine has taken on a more literal meaning. Since I'm unable to run, and biking just hasn't been as appealing to me (I like to bike outside, but it's been cold), and I want to keep up my cardio, I've been swimming...a lot.
I've been trying to get to the gym 4-5 times a week, and I've really been enjoying the pool. It doesn't hurt my knee, but I can definitely feel that I've been working hard. Each time I hop in the pool, I make it my goal to swim at least a mile plus a cool down. It may not seem like much to some people, but for someone who, save for a few weeks this past summer, hasn't done any serious swimming since she was 12, this is a big deal. So far, I getting about 1800 meters (200 more than a mile) in about 45-50 minutes, so not too bad.
Still, though, I'm working to improve. I want to go farther, faster, and be less tired at the end. My current routine involves 2 laps breast, 2 laps free, and 2 laps back. I repeat this 11 times, and then I finish with 2 easy laps of breast. Today, I decided to change things up a bit, so I made this 2 laps breast, 3 laps free, 1 lap back. I went faster overall, but boy was I exhausted, and by my 11th set I pretty much did all breast.
Anyway, the point in all this is that I've found something that I'm enjoying. It's not perfect, because I still wish I could go out for a run, or do some jumping jacks, or even a squat. In the mean time, though, I'm going to just keep swimming.