When I play guitar for a while, my arm gets tired. I don't think theres much tension when I'm playing, so is this normal?
Well you could be holding the pick to hard and or in a funky way. Or if your newer its normal.

Q: How do you get a guitar player to play softer?
A: Give him some printed music
It's normal unless you have been playing a lot. Whenever you start using muscles that haven't been exercised much there will be soreness and stiffness. Just keep playing but take breaks every once in a while to let your arm rest.
well yeah with extended high energy playing but it depends are you a rookie and what are you playing for instance if you playing something like sweet child o mine you really shouldnt get tired but say your playing like death metal then its normal you just have to build stamina.

also make sure you play loose dont tense up it causes fatigue and in the long run health problems.
its not usually supposed to get 'tired', you are using to much arm in your playing. Use your wrists too.
Quote by hell_monkey
Lmao pantera? you'd think obama listened to some tupac or something
It sounds like your picking with your arm and elbow. Instead of picking while bending at the elbow for appropriate angles, pick by bending your wrist. Much more comfortable, and its the proper technique.
it's all just coming back
it's all coming back

it's all coming back to me