Can you explain how you usually exercise? One possibility is that your muscles in other parts have become bigger, but you usually ignore the training of your arms, so it seems that your arms have become thinner. Another situation is that you have a regular and systematic training plan, few arm training items, unreasonable nutrition supplement and insufficient rest time, which all affect the effect of exercise.

You can tell me your daily exercise plan and I'll help you improve it.

Pure hand tour, still hope to adopt, have questions.

My very best wishes to your health