Learning curve

I'm slowly learning what I should not do for my knee. Today I tried out an arc trainer/elliptical thingy for my cardio workout and by the end of that my knee is stiff. Not sore, but it does seem to stress out my knee a bit more than it should when it's on higher resistance. Maybe I should lower it a bit. I think it's a bit too close to a stairclimber for my knee to like it very much. Pity. It was kinda fun. So, so far that's swimming with careful form, walking fast and the regular exercise bike that don't bother it so I know I can do those without harm.
I'm just trying to vary things up a bit, but I suppose I'll learn slowly what machines are not a great idea to use. I'm trying to ride the fine line between building muscle and pushing too far and hurting and having to stop. Today was close. When I noticed a stiffness at about 10 minutes on the machine I probably should have stopped. I decided to keep going and see what happened...dumb I know. No real harm done but still. I should know better. Perhaps I need to have a stronger knee first...we'll see. All I know is if I could heal my knee with attitude I'd be better by now :)
At any rate, I did do my leg/knee exercises and other arm & sit up stuff and after the robot clocking me off at 379 calories I'm in for another day. I'm all stocked up with healthy food and I know it'll be a good day. It'll be another 15 hour day here at Chez Laboratory so I have healthy meals and snacks and coffee (precious coffee).

The anti-Jared said something the other day. He was listing off a bunch of "happiness is" things (reminded me of the old Peanuts book I had as a kid). One of them was having to get your ring resized because you're smaller. This struck me, as I need to get mine resized again - I keep putting it off. Made me smile when I thought about it. When your fingers have shrunk you know you're onto something. :)
With any luck this will be a good day! Have a good one everyone!