Right now I am about 2.5 hours from the finish of a 6.5 mile trail run and I feel unbelievably fantastic. I am alert, energized, but very calm and relaxed. I feel this way after just about every run and most other workouts as well.
The longer I run the longer the runners high lasts. When I do a run that goes into the teens in distance The runners high can last for a couple of days.
It really is a fantastic feeling you should try to achieve it and when you do think of me.