I’m right-handed and my right bicep has always been slightly bigger than my left. Lately, however, I’ve noticed that my left is getting a lot bigger than the right. The funny thing is, it feels like the right one, the smaller one, is stronger. I worked my bi’s yesterday. The left fatigued faster and is sore and tense today. Any ideas on why this is happening?
It’s not uncommon that the arm of the non-dominant hand gets larger. The reason is that growth happens during recovery, which the non-dominant side gets more of.
patman - check out your muscle insertion points to see if both are the same on each arm. i suspect they are not and due to this different muscle “rigging” the muscles develop out of symmetry when loaded the same. my top delts are this way and you can clearly see the differing insertion points of each top delt. my left delt is smaller in size, but inserted further down my upper arm and consequently has a better mechanical advantage. my right top delt does not insert as far down and to handle the same load the muscle is more developed to compensate for the disadvantage. we all have this type of thing going on all over our bodies and some are more noticeable than others. hope this helps. kevo
That’s natural. The reason it happens is BECAUSE your right arm is stronger than your left, so when you load your arms with equivalent weight, your brain recruits more fibers for your right arm, resulting in less damage versus the left arm, which subsequently grows more than the right. Everything balances itself out pretty much after a few years of training.
I would tend to agree with Kevo’s assessment. The only part of your post that I had a real problem with was when you stated that things even out eventually. I don’t agree. I think bilateral asymmetrical problems would only increase unless you do something about them. For example: I think one would tend to baby the weak arm while the strong one took over. This would of course exacerbate the problem. Am I wrong? Coach Davies, Charles Staley? Anyone?