Tensing up arm when shredding, bad?

I don't think by relaxed that everyone means relaxed like when you are asleep. Of course there has to be some tension, but a kind of relaxed CONTROLLED tension, not tense like when I bang my fist on a vending machine that just stole my dollar. :lol:

..exactly!

The kinda tense I'm talking about is my mainly in my forearm and the back of my arm (dunno what its called, but if you hold out your arm horizontally, its the part facing the ground on the part of your arm that connects to your torso). Are these the muscles that you use to go up and down real fast, or am I tensing something unnessesary?

There is more than one way to achieve rapid alt. picking. The specific method will depend on one's particular anatomy, strength, coordination, pick stiffness, string gauge and even the target speed. In every case, some pairs of opposing muscle groups will be brought into play to achieve the back-and-forth or circular or hybrid motions (dynamic movement) and these muscles with some others will be tensed in opposition just enough to provide the necessary pick resistance/compliance (static tension -- how hard the pick attack will be). Many players, myself included change the actual motion and direction and therefore the key muscles in use based on required speed, desired sound, number of strings struck and movement from string-to-string. There is no simple advice or formula that will work for everyone. But one thing we all learn is to avoid over-tensing the muscles in play, and to relax (relative term -- nothing is totally relaxed) the muscles that are secondary and tertiary. The player knows were extra effort is being applied, but the observer will think it all looks relaxed and easy.

As far as shredding goes, tremolo picking is not the only technique used, and often it is not the most important. The speed in single note shredding usually incorporates a lot of fluid sweep picking, HO's and PO's and, sometimes, tapping of various types. And yes, I be willing to bet several of the posters on this thread can actually shred, blutic. It's not really the most difficult aspect of playing guitar.

I think "shredding" needs to be defined. When I think of shredding, I think of the 80s virtuoso style and people like Vai, Malmsteen, VanHalen, etc. I don't consider the fast chord strumming ala Metallica, Megadeth, etc. to be shredding. [Sorry about the oldie refrences, but I started playing in the 80s ;)]

I often see music store heros trying to shred by tremelo picking random notes or tremelo picking scales. You can see the tension there. True melodic shredding cannot be done with stiffness and tension. It's the lefthand / righthand mental connection that allows the speed to come. Look at every magazine, book, DVD, etc. and you always hear the instructor say things like "play this slow, to play it fast", "don't tense up, just relax and the speed will come", etc.

Maybe I used the wrong word when I said shreding, what I am talking about is something like this from 99 red balloons:
D---------------------------------------2 2 2 2 2 2 2 2 4 4 4 4 4 4 4 4
A-2 2 2 2 2 2 2 2 4 4 4 4 4 4 4 4 0 0 0 0 0 0 0 0 2 2 2 2 2 2 2 2
E-0 0 0 0 0 0 0 0 2 2 2 2 2 2 2 2-----------------------------------

repeated many times very fast.

Blutic, I suspect we may agree on what shredding is:

Your examples hold up for me.

On the flip side, I posit that Al Dimeola is not a shredder, even though he has a lightning fast and super accurate tremolo picking technique. Nor was Johnny Ramone, despite his machine-gun-rapid-never-ending downstroke strumming.