After my long run on Saturday I couldn't believe how good I felt. When I woke up I didn't really feeling like running. I didn't have my running partner, I was tired, and it was freezing outside. I was thinking I should stay inside and snuggle up on the couch with my kiddos. But in the long run (that seriously just happened) I couldn't miss it. Once I got going I felt like I could have gone forever. I had to force myself to turn around at 4 miles so I wouldn't overdo it too soon after the marathon.
Just remember, you usually feel better after a run than you did before it.
I've done a lot of exercieses (P90X, Insanity, cycling, swimming, etc) and nothing else gives me a feeling like a Runner's High. I freakin' love that feeling!