For the past few days, I couldn't sleep properly due to jet lag. I ended up sleeping around 2 -3 AM, watching downloads or reading something.
But yesterday I ran again with Alvin in BGC for more than an hour and we covered a distance of 10 kilometers.
And lo and behold, I fell asleep at 10PM!
So that's my Reason # 5 for running - so you can fall asleep quicker and better due to this exercise :)