I seemed to be mostly recovered from my "training camp" by Sunday. The Stony Creek XC race was also Sunday, but I decided that racing for 2+ hours probably wasn't the best idea; for whatever reason, I also just had no desire to race... maybe I've raced there too much over the past few years. I don't know.
Anyway, I decided to do a LT field test instead; still a hard effort, but much shorter. Even though the basement was a little hot, I still made a pretty good effort. I ended up producing my second best ever power number (my best ever at this point in a season), so I was very happy with that.
My heart rate was on the low side again though, and I'm really not sure what to make of it. Prior to this year, my average heart rate was consistently around 186bpm for these tests. This year, it's been noticeably lower, yesterday was 179bpm. I definitely pushed to my limit, so that wasn't the issue. I suppose I could put it down to the general variability of heart rate, fatigue from my riding earlier in the week, etc, but it seems like my previous tests were so consistent... I don't know. I'm not going to lose sleep over it, but I would like to find an explanation.
The other thing that cropped up again (which may be related to HR) was that I had trouble finding a good gear to ride in. The same thing happened last Fall. Seemed like I had to spin the gear that I used for most of the test a little too fast, but the next gear was a little too hard on my legs. I see now that there is a 2-tooth step between the gears I was using, so that partially explains it.
It seems to me like, if you're not in an optimal gear, you may not be able to hit your "correct" threshold heart rate because you're not really hitting your threshold power.
It's funny that I get all hung up on these numbers when I do the tests. Most of the time, my only "training tool" is a stopwatch (and a GPS if I'm on unfamiliar roads). As it is, my HRM is pretty low-end, and my "power meter" is a calibrated trainer... so, it's probably best not to get too carried away with this stuff...