Hundreds of articles about weight loss ...
Just wondering, I've stepped up my exercise quite a bit recently, mainly brisk walking and step aerobics and the other day my daughter told me one of my calves was quite a bit bigger than the other, (the right one) and she is quite right,it is! Eeeek! Is it possible that I'm using the muscle in this leg more - which is why it has become bigger? Was getting worried I had some kind of lurgy...lol
With increasing exercise, particularly impact-type exercise like step aerobics and brisk walking there is a greater likelihood that your body will place more demand on certain muscles, i.e. like the calves. It is very plausible that you are loading your calves more and also plausible that one is dominating over the other which is resulting in the development of a slight difference in shape and size.
If you aren't experiencing any accompanying discomfort, pain or tenderness over the larger of the two calves then it is unlikely to be a medical issue (lurgy!), however if you were in any doubt I would urge you to seek advice from your GP. However, with the likelihood that it is merely muscular increase in strength through training what it does signify is that you may (biomechanically) be loading your weight unevenly through the legs.
I would urge you to consider what injuries you have EVER experienced with your lower limbs, especially twisted/sprained ankles, calf tears or/and knee problems. Often previous injury issues can lead us to unconsciously load the legs differently favouring one to avoid excess stress on the other or due to previous injury we have remnants in the form of scar tissue, reduced flexibility or muscle weakness.
When you are out brisk walking make sure you try and walk as evenly as possible pushing off the legs with the same amount of effort and with minimal excess movement/sway from the upper body. Also, another little hint I would give you for when you are brisk walking, to help protect your calves, but also make the whole movement stronger is to try squeezing your gluts (butt muscles) as you are walking! Not easy to start with but possible so keep trying.
Hope this helps