#1
I've been having some trouble in alternate picking syncopated beats while standing, like Metallica's One and Motorbreath riff...
Sat down, I can play them quite well, but stood, I lose some precision and have to tense my arms...
What can I try?
#2
You should try adjusting the strap to different lengths. I found that I can play a lot better with the strap higher up.
#3
Quote by unyinz
You should try adjusting the strap to different lengths. I found that I can play a lot better with the strap higher up.
Most people can.
I could be wrong... but I think a lot of new players just don't realize how high up the guitar is on their chest when they practice hunched over in a chair.

And inevitably... there's a lot of questions about difficulty playing when standing.

Personally, I found a comfortable standing guitar height and that is how i practice 80-90% of the time (standing up).
My belief is to practice how you will perform. YMMV