Insufficient System Resources
I switched up my routine the last couple of weeks, doing a lot of mountain biking when I normally head for Krav class. The result is that this week my legs and back are recoving from a pretty heavy cumulative workout, and I'm doing a lot of stretching to make sure they stay healthy.
I hadn't been following up on all that by getting enough sleep. I didn't really put it together exactly what was going on until yesterday, when my back really hurt, despite having had several days to recover from last week's bike rides.
The pain really felt like I'd overworked the muscle, rather than a pull or anything else with a single discrete cause.
Overuse injuries are rarely the result of just "overdoing it" on a single run or ride. It's certainly possible, but not usually the case for me.
Overuse injury is usually the result of several workouts (short or long) with insufficient recovery time in between. Doing three rides in a week may or may not have been enough by itself, but adding in insufficient sleep, I was taking away a crucial resource my body needed to repair itself between rides.
After last night's boxing class, I took a few minutes to stretch and do some baby rolls, which are my new favorite thing: part massage, part stretch, part meditation. When I got home, I did a 25-min. yoga session, and got to sleep by 11:30, which gave me about 7½ hours of sleep last night, about 2 hours more than I got on Sunday night. It made a world of difference to my mood, my mental faculties, and to my back: I can feel that it's now in proper post-workout recovery mode, rather than simple damage control.
So, the moral to the story is, once again: I need to sleep a minimum of 8 hours a night. Last night was a good start. I need to get back where I was a few months ago, getting 8+ hours every weeknight, and sometimes more on weekends.