I decided I should really go make sure that I can run 5 kilometers, just to be on the safe side. I mean, it would be terrible to show up the day of the race and not be able to finish or something. And it’s not that I haven’t been working hard to get in to shape, because I have. I just have never been much of a runner.
So I went off to the gym yesterday morning, hopped on the treadmill, programmed it for 3.5 miles, set it for random, and picked level 4. Then I plugged in my headphones and looked for something to watch on the little treadmill TV (I went with the A-Team Marathon on TVLand) and pushed start. It went ok at first, but by 25 minutes in, I had only gone about 1.7 miles and I was about ready to die. At this particular gym the treadmills are right up against a mirrored wall, so whenever I looked up from the TV, all I could see was my bright red flushed and sweaty face. My heart rate was way up and my legs were tired. I had to slow down to a walk a couple of times, and I eventually ended up down at level 1. I ended up doing 3.25 miles, which took me 45 minutes! Yeah, I guess I’m not quite as fit as I thought I was. And today my leg muscles hurt. A lot. I’ve been gimping my way around the house all day like I’m 90 years old.
As much progress as I’ve made, I’ve still got a long way to go. I didn’t feel up to running again so soon today, but I did do one of my exercise DVDs. I’m committed. I will get fit, dammit. Too bad it involves so much work and so few donuts.

If only donuts were healthy. That would be a wonderful world to live in...
Don't take it for granted that all treadmills/ellipticals/stationary bikes are created equal. They aren't all necessarily calibrated.
I've been on machines that look identical, one day 20 minutes = 120 calories, the next day 325... I chose to believe option 2 :)