Originally Posted by patentcad
It's really just endorphins flowing in your system. I've felt fantastic on bike rides. But frankly I used to occasionally get 'runner's high' that was more intense than anything I've felt on a bicycle. Two factors: cycling is harder in many respects, and you don't always have the same consistent high elevated heart rate that distance running demands due to terrain variations in cycling, coasting, etc.
On the other hand I typically feel good AFTER cycling, and often GREAT. And that's why I do it.
Did you mean to saying running is harder in many respects than cycling? I hope so! I can't for the life of me see how a non-impact activity with variable output is anywhere near as demanding as running.
Or where you referring to the demands of keeping a bike upright, maintaining situational awareness, not getting schwacked by cagers, etc?