Want 2 gain 1 inch of biceps in a month?

You can work on your biceps and triceps and that muscle in between the two. And you can do it twice a week. use 60-75% weight. Vary your routine. To get a burn try 6 reps with 75% (say 25kg) weight and immediately after do 6 reps with 70% (say 20kg), then 6 reps with 65% (say 15kg), no rest in between. Rest 4 minutes then repeat do another set. Do biceps and triceps and reverse grip bicep curls (middle muscle). By doing bi and tri you will grow both sides.