Why is my left bicep bigger than my right?
Okay so I was doing a little fun flexing the other night in front of the mirror and I noticed my left bicep is bigger than my right! Not by a lot but I can definitely tell the difference. I use both dumbbells and barbells and try to focus my form all the time and I am right handed.
We are not completely symmetrical. Muscular size is a function of use. My left bicep is definitely larger than my right, but I am left side dominant. I would be curious to know what exercises, ADL, or other past impressions that one bicep may have experienced differently than the other? There could also be a genetic influence. If it is a concern, what would you suggest to a client in the same situation, assuming they wanted to cause a change?
It sounds like it shouldn't be much of a bother other than aesthetics. Danielle was correct in that no one is perfectly symmetrical. I'm right-handed and my upper left arm is 16 inches and my upper right arm is about 15.7 inches. My right forearm is larger than my left forearm but not by much. Your muscles are probably a lot more noticeable to you than to others. I'm that way a lot. I see myself so often that I notice all the small flaws, but the small stuff isn't noticeable to everyone else, they aren't looking that hard.
An uncoordinated side can usually be bulkier and stronger because it has less use and more time to repair itself.
I hope that this helps.
If you are right handed and your left arm is larger, and you are middle age and suffer from any symptoms of thymus problems, like night sweats for example, its possible that your thymus may be putting out anti-acetylcholine receptor antibodies that are slowly and permanently disabling the connections from your nerves to your muscles.
The muscles that are used with more frequency are effected more, so your right arm would atrophy more than your left.
When this condition becomes extreme its called Myasthenia Gravis. But in early stages, it may not show up on blood tests.