I ran 20 miles (32 km) yesterday in a little over five hours. After the run, my feet hurt for a few hours but overall I felt fine. Right now I feel almost completely recovered with only a slight amount of soreness in my muscles. I used to think that if you trained well for running long-distances, you should have minimum amount of pain and soreness. Now I think it is not the amount of pain but rather how soon my body overcomes it so I can go do it again. I think this philosophy applies to life too. The faster you can recover from a setback, the stronger you will be.
I'm off to donate some blood now and later will spend some time in the jacuzzi and sauna at the gym. I have to train breathing in low-oxygen environments and the closest thing to that in Florida is a sauna.