I believe that bigger biceps can be achieved much faster by training them twice a week in the right manner. Most people train biceps the same way they train legs and chest: once a week with the usual rep and set scheme.
Biceps are different. They are a smaller muscle and you can get away with training them more often. This especially works for hard gainers who have struggled with gaining bicep size for a long while.
You have to train them correctly though. Don’t overtrain them by doing a bunch of sets and reps.
Bicep workout 1 – Choose a mass builder for the bi’s. Straight bar curls, dumbell curls, anything but isolation movements like “seated concentration curls” or isolation bicep machines. Now go heavy to failure and only perform 2 sets. Remember, we are going to be hitting bi’s again in a few days so there’s no need for further sets, and actually, there is NO NEED for further exercises either. That’s it. 2 sets of curls and your DONE.
Bicep workout 2 – This should occur 3 or 4 days after workout 1. Now you want to focus more on concentration work. Choose a machine or a seated isolation movement and curl the weight up for a higher rep count that on bicep workout 1 (12-15 reps for workout 2). You can also perform some partial reps to work the peak more at the end of your normal set. Again, only 2 sets should be needed if you go hard enough.
Give this a shot and if you do it right you should notice bigger bicep development after your first month.