to pantallica: If I´m doing Alternate picking it´s less tensed, but not relaxed. Strumming chords: Not really tensed i would think, but the left shoulder is more relaxed. But for example when i play some fast metal riffs with mainly downstrokes like blackened for a longer time it gets quite tensed! I don´t think that i wanna play too fast because I always start slowly and also put the bpms up slowly.

to progg: might be that standing up helps, but i don´t feel comfortable with practicing while standing, or should I really do that?