A Sweet, Sweet Jog

I had a sweet, sweet jog tonight. I didn't even get to the track until late so it was nice and cool out.
I pulled off an 880 followed with two 440s and two 220s and then I finished off with four quarters. I tried running or fast jogging the quarters, lifting me knees higher than usual.
I felt really good after. Like I'll be able to do the 5K in a decent time, jogging the whole time, maybe even a slow run at some point.
Woooooo!
I did really feel it in my knees at the end. That makes me nervous. I don't want to do anything that'll mess up my knees. I wear a brace-type thingy on the right one. I might have to get one for my left knee too if I plan to keep this up.
I'm hoping to get out twice more this weekend and do some major distance. I took three nights off in a row and didn't mean to so I've got to catch up again.