spin last night

I finally made it to spin last night- though I ended up with only five hours sleep because I had "homework" to do- though I thought that a bit of spin wouldn't be such a bad thing. I didn't even enjoy the class because I was trying to do my homework in my head. The instructor would be saying sit down and I would be standing up. It was a very bad idea regardless but I feel terrible because I haven't done any other exercise this week other than the two spin classes- tomorrow is supposed to be another 16km run but I don't know how I will go.
I have been so active all week and frantically trying to get enough water on board in the evenings means that I get up three times in the night to "powder my nose". I have a nasty bruise on my upper thigh- 6cm across and suitably purple and blue as well as other random bruises I can't recall occurring. Thankfully the course is over, we all passed and I can go back to my normal routine.