Heyy! maybe you are not doing a proper workout or consuming a nutritional diet. Your muscle grow on 2 factors-
- Effective workout plan- You should choose an effective workout plan that helps you target your muscles properly and will help them grow. Here are some effective biceps exercises.
- Incline Bicep Curl
- Twisting Dumbbell Curl
- Concentration Curl
If you want a proper workout plan then go through this article How to build bigger arms Click Here.
- Consume proper nutritional diet- Along with exercise, you should consume a proper nutritional diet that will help your muscle grow stronger than before.
For gaining increase carbs intake like rice, oats, mass gainer, pasta, etc in your diet which will help you in growing your arm size.
Hope this answer will help you. All the best and stay strong. Thank you.