I blame swimming.
When I go into open water without nose and ear plugs, I get sick. It might be one of above don't have functioning defense mechanisms, or it's psychosomatic, or whatever, but it happens. So for the past few days, I've been trying to throw off a fairly mild infection.
I'm also having some moderate low back pain. It always follows the same pattern: the muscles along the spine are tied in knots. After a few days they loosen up a bit and I can get the vertebrae to crack, and that helps feel better too. After a while I only feel pain when I go from sitting to standing, or standing to walking, or walking to running. It's the transitions that hurt.
Then, hopefully, everything resolves and I can go back to my normal healthy life.
Between the illness, the back pain, the heat and the deer flies, it's been a pretty cruddy week for exercise, and even worse for studying. But tomorrow's another day...
M: 20 minute swim
F: 10 mile bike
S: 15 mile bike, 2 mile run