So Tired

I haven't run for about a week and a half, due to an evil combination of weather, long hours at work and a cold. Today I finally felt well enough to get out, but it seems I suck more than I did a mere 10 days ago.

My 32 minutes of running and walking amounted to a mere 2.25 miles tonight - max. That's almost a half mile less than last time. And I feel much more tired tonight than I did last time, too.

So, what's going on? Is it because I'm still recovering from my head cold? Is it because I took too much time off? Is it because I wasn't really doing spectacularly well to begin with, so it was much easier for me to get worse? Maybe it has something to do with the copious amounts of Diet Coke I had to make it through the day?

It might be something else, though. I did make a conscious effort to take it easy tonight, since it's my first time out in a while. I also checked my heart rate and adjusted my effort down a lot because at the end of the first segment, my heart rate said I had reached maximum effort (according to the standard VO2 Max formula), even though I didn't feel quite as exhausted as I think I would have had I actually reached my max. Maybe my max is higher than the formula suggests it should be, and that's why I didn't feel like I was working that hard. Maybe I'm just convincing myself that I'm tired because according to the formula, I had a really hard workout.

I suppose I could clear that last question up by just having my VO2 max tested. Of course, that might be the sensible thing to do, which means I probably will never get around to doing it.