Rocks in my underwear

I went out running this morning and I felt like I had rocks in my underwear. Let me explain... I was moving in slow motion and every step was an effort. I decided that when I was not looking someone loaded up my underwear with rocks and that was why I was running so slow and with such effort!

Then I kept thinking....was it because of the time change? was it because I only had a small bowl of oatmeal the nite before for dinner? did I suddenly turn old? or was it because I was loaded down with rocks?

I will have to keep you posted on what the actual cause is. I will go out for another run tomorrow and report back on the problem.