I'm right handed, yet somehow my right bicep gets tired

>>36485986
yeah this happens for me too

my left arm is bigger and stronger but im right handed...

>>36485986
>>36485998

Are you internet fappers?
Many otherwise right handed guys use their left to fap so they can use the mouse to browse while doing so.
Much of the gainz the dominant hand of men had in the past was from fapping, in the new age of computers those gainz now go to our offhand.

>>36486053
Nope. I'm a lefty on the mouse kinda guy. The computer mouse.

I don't call my dick "the mouse" btw. I call it "Ox Bellows"

same here.
Whenever Im lifting I do more curls with my left hand and,overall, feel less fatigue when lifting heavy on my left hand from any upper body exercise. Shit is weird yo.

Because your dominant hand is used to the motions, so the muscle around it are built up more so work more efficiently

Your off hand hasn't had the chance to optimise that shit, so the bicep takes more of the strain day to day and is therefore stronger

>>36485986
Right handed finesse, left handed brute strength.

Right handed sword/spear, left handed shield.

It's evolution. The people who didn't have that died on the battlefield.