You know how martial artist are supposed to yell before they strike things? You know what I mean, that crazy looking man screams like a maniac before putting his face through 4 inches of concrete.
Well I have a theory on why they do it. What must you do before yelling? Can't figure it out? Try yelling right now from deep within your chest. If you did awesome, you have probably figured out what it is. If you didn't you are a pansy. Before you can yell you need to breathe in deeply! This is obviously going to affect how hard your face hits the concrete because all your muscles get a little bit of extra oxygen. Secondly it helps them to steel themselves mentally. The yell let's you focus your energy on breaking things. Half of this is will power and yelling can really help. Mind over matter. (normally this would be place to start talking about observed based reality, but I don't have all night)
The final reason it is done is because it's freaking terrifying! If I was one of those concrete slab I would be trembling in fear of the force about to smash into me! The same goes for people. If some guy yells like a bear and then moves to punch you I'd run like a little girl as fast as I could away from the scary man.
p.s If you want to see awesome videos guys hitting things with more power then a sledge hammer with their face check out Fight Science It's educational! also they break things.
p.p.s I will be unable to post anything until Monday I think. Unless I can get mobile blogging working, but I imagine that writing entries on a cell phone will be unpleasant to say the least.
p.p.p.s Did you know that p.s stands for post script and was used to add things to good ol' fashioned hand written or typewrittered (typewritten?)? People just kept adding more post post scripts to update the letters to infinity! Now you know. Part of our heritage.