Best way to regain your energy after being sick?

I was quite sick and housebound for three weeks. I slept and Fluthered whilst in bed most of the time (and watched the occasional movie). I’ve been taking my antibiotics for a week now, and I have two more left to take (I’ll be done Friday). I’m feeling great now, but, man, I have little energy. I could easily sleep all day and am winded after being active for say, 15 minutes.

Other than getting plenty of rest, what else can I do?