Yike! Is that the "Gungan Style" guy everybody talks about? Hmm. Anyway, I assume the ponytail in question is at the 0:38 point-- the lady running on a treadmill. That's a very high pony, so one's hair needs to be pretty long. I did wear them like that when my hair was longer. Mines just below shoulder length right now, so I wear it low when I do.
Barbie, I would think you would wear a ponytail often, being a runner. It's often windy in my part of the world, so binding hair one way or the other is pretty necessary, lest it be in your face and such. I understand it's not good for the roots the let hair bend back and forth in wind a lot.