High Altitude Training Mask?!

Saw a bloke running with one of these today: http://www.trainingmask.com/products...-MASK-2.0.html

Is he a fool or is this the new trend for triathletes?

I think this current craze was adopted by MMA fighters a few years ago with this...........

http://www.mmagearguide.com/wp-conte...ining-mask.jpg

Now it seems to be trickling down to something less full on.

Any evidence it works? I am not thinking of getting one but the physiological response - if any - would be interesting.

Surely it only makes it harder to breathe without the physiological benefits associated with training at high altitude, could you get the same effect with a nose clip and a couple of Buffs??