Why my left bicep won't grow

[Arsenal]

I've been training on and off for the last 4 years(yeah, I know..I'm lazy), mainly to keep fit and look like a man :)

My main problem is that my left bicep has no peak, is soft to the touch even when flexed and basically looks like a bicep that has never been worked on. My right bicep is in stark contrast to the left. I know that left and right are always different, but the difference shouldn't be this big, should it?

[Stephen Johnson]

Do you train each arm independently with dumbbells, iso-lateral machines or cables? And did you ever injure your left arm?

Ironman magazine once used a bodybuilder - whose name escapes me right now - as a shill for their Muscle Meals product. This bodybuilder's flexed right arm was 3" bigger than his left - although the left arm was 20". I assume that you're right handed.

[Arsenal]

Yes, I'm right handed. I've never injured my left hand, unless cuts and scrapes count as an injury ;)

I have done concentration curls on my left, but I usually have to give my left arm a little support with my right to complete the set. That's about all the isolation I've done for my arms.

[Stephen Johnson]

I have done concentration curls on my left, but I usually have to give my left arm a little support with my right to complete the set. That's about all the isolation I've done for my arms.

You might want to switch your upper body work to dumbbell, iso-lateral machines or cables so you can work each arm independently. Start at a weight that your weaker arm can handle, and use that for both arms. Increase the weight as the weaker arm gets stronger. Don't worry about your stronger arm not getting worked hard while the weaker one plays catch-up.

BTW, how's the strength of your left tricep?

[Matt Z]

Contrary to popular myth you cannot give your biceps a peak by using various exercises. You can make you biceps larger, but the shape is determined by genetics.

[Matt Z]

Also, the human body is rarely 100% semetrical. For example, your left foot may be a half size larger or smaller than your right foot. Likewise, the shape of the left bicep may be somewhat different from the right one, even if both are equal in strength.

[Guest]

Stephen,

Thanks for your suggestion. It will be frustrating to train my right bicep with weights it can easily handle, but I'm certainly going to give it a shot to increase the left bicep's size. Do you have any other suggestions? Btw, what do you mean by iso-lateral machines?

Matt,
Thanks for your help. I know that the left and right are often unequal (slightly different shoe sizes etc.), but my left bicep is significantly smaller than my right one, hence I had the question.

[Mog16]

one question I might ask (though kinda awkward) is do you flex a lot with your right arm? I personally have the problem of asymetry and I have actually been taking measures to prevent this for about a year (all DB sets lead with left and only match with right) but I still have a significant imbalance which I attribute to my (very vain) love of mirrors and flexing. Due to me being right handed it is easier for me to flex my right arm and when I try and flex my left arm it is actually difficult to achieve a strong flex. Just a thought.

[Stephen Johnson]

Stephen,

... Btw, what do you mean by iso-lateral machines?.

I'm not sure that I used the correct (generic) term, since iso-lateral seems to be a trademark of Hammer Strength equipment. What I meant was machines that have independent plates or weight stacks for each side of the body. Like this one.

Hang in there, I know how you feel. Years ago, I broke my left arm, and when it healed, it was shrivelled to about half the size of my right arm. I followed a similar program to get it back to near parity with the uninjured limb. It seemed to take forever, but I did it.

[Matt Z]

PS.) My biceps also lack any real peak, which combined with big triceps (one of my most well-developed muscles) makes them look a lot smaller than they really are.