The growth of arm circumference needs the accumulation of training. Compared with the muscles of the chest and thigh, the arm belongs to a relatively difficult part to grow. If ordinary thin people don't exercise regularly, it is actually very difficult to grow to 30cm.

It is difficult for ordinary fitness enthusiasts to reach 40cm without several years' training. Even if you become a professional player, it takes not only time to exceed 50cm, but also a certain height and talent.

They use their arms, carry, write and hold mobile phones every day. They have been exercising. They have adapted to long-term activities and have a strong tolerance for fatigue.

Ordinary training is no longer painful in the eyes of these weather-beaten muscles, and the arms need real training stimulation. The number of biceps training group is generally higher than other large muscle groups. If you are a family with long-term arm growth difficulties, try to directly increase the training volume by 50%. I used to practice 4 groups, but now I do 6 groups directly.