Forum:How can I run?

I guess that it is a silly question, but how can I make my Arisen run?

I mean, I 've seen in videos that other gamers make their character run (example: https://www.youtube.com/watch?v=ogigrWONjjQ) but I can only walk. The more light weight the faster I walk, however I can't find how to run. I am playing the game on a ps3.