I finally discovered the main flaw in my piano playing. I was wondering why I could never play very fast and when I did anything intensive my arm became fatigued rather quickly. I discovered that my problem is relaxing tensed muscles! I did a test where I played some percussive left hand riffs and with my other hand felt my forearm muscles in the left arm. They started of ok then as I played for a few more seconds I became fatigued and I was very tense. The fact is, I never really learned or thought about relaxing muscles after using them, I just kinda figured they'd do it on their own. But I was so wrong, Now I really need some ways to practice relaxing muscles right after tensing them.
I guess the key to speed is learning to relax muscles as quick as you can tense them and that it becomes natural to do so. Know any good ways to practice this? I was doing stacatto exercises where I play a note or octave very loudly and then try to relax my arm instantly, It's hard but at least I'm now I understand what's wrong with my technique. :lol:

Don't think about relaxing as an action. As in, you shouldn't think of it as, "relaxing them instantly" you should just "be relaxed." Being relaxed is a state your physical and mental being is. Just always remember that, and try to incorporate relaxation wherever you are.

Ok, may'be but it's my left forearm, it won't relax, I dunno why, but since I study anatomy for drawing, I'm aware that the top of the forearm muscles have nothing what so ever to do with pressing down on piano keys so why oh why do they tense as soon as a play an octave in the left hand? How can I learn to relax them?
If I really concentrate I can play with out tensing it but it's difficult to play octaves in my left hand with a relaxed forearm because I got stupid bad habits in my playing I'm working on fixing right now.