The tension when you're playing faster comes because you don't want to make any mistakes and that's ok, so your body concentrates too much on that and that generates the tension and the extra pressure in your pick hand and sometimes in your thumb of your left hand. Be carefull because those things could bring some tendons problems.
A good way to liberate the tension is too practice a lot at a slow speed so you can increase your precision and that allows you to play more confortable at a higher speed. The other way is to practice a lot to the full speed and beyond so when you lower the speed to the real time you'll feel relaxed and confident because you can play it twice as fast more or so. That's the advice Paul Gilbert gives (to play something good and full speed you have to be able to play it twice as fast), and John Petrucci, when he says that he always pushes a lot beyond the speed limit of the lick that he wants to play.
So, the those ways could help you to release the tension but the best way is also to be aware of that state and correct it when it happend. In order to do that you have to pay attention when you're practicing not only to the fingers on your fretboard but to your breathing and all your muscles so you can work on the relaxation while you're playing.
I hope this help you a little bit.
You are at GuitarMasterClass.net
Don't miss today's
free lick. Plus all our lessons are packed with
free content!