Reading or Practice?

Yesterday after work I did nothing constructive.
Today work was much better, and I know I'm behind in my schedule to practice all my techniques, but I still have the urge to sit and read my book or play cello for the rest of my day.
I believe there are several factors to this.
The largest is the weather. There are no flat surfaces where I can easily practice my techniques and forms.
Next factor: I'm reading a wonderful book!
After that I'm just lazy.

I practiced cello for hours and hours on Wednesday. Which brings me to another topic, my vacation:

It was amazing. Completely perfect in every way. I will write a full report later.

As is, since I'm feeling lazy and un-motivated, I will do pushups, crunches, jog, and practice karate.
[edit: it was too dark out for karate, but I did everything else!]