Muscle building refers to increasing muscle mass and muscle mass through exercise and diet. For thin people, it may take more effort and patience to gain muscle, but through correct methods and perseverance, effective muscle gain goals can also be achieved. Here are some key steps to help thin people gain muscle:

1. Increase calorie intake: In order to gain muscle, you need to provide enough energy to support muscle growth. Make sure that your daily calorie intake exceeds your basal metabolic rate, that is, the energy your body needs at rest. Increase the intake of protein, carbohydrates and healthy fat to support muscle growth and recovery.

2. Increase protein intake: protein is the key nutrient for muscle growth. Increasing the intake of protein can provide amino acids for building muscles. Foods such as lean meat, eggs, fish, beans and nuts are all sources of high-quality protein.

3. High-intensity strength training: Weight training is an important step to build muscles. Stimulate muscle growth through high-intensity strength training. Training with less repetition but heavy load, such as 6- 12 repetitions in each group, is helpful to stimulate muscle growth.

4. Proper rest: muscles will grow and repair during rest. Give the muscles enough time to rest and recover, and usually repeat the same muscle group at least 48 hours later.

5. Eat more meals and less: eat more meals every day. Make sure to provide enough protein and carbohydrates before and after training and before going to bed to help muscle growth and repair.

6. Supplementary materials: Sometimes, some supplementary materials, such as protein powder and amino acids, may be needed in the process of muscle gain. But please consult a professional doctor or dietitian before use.

7. Persistence and patience: muscle training is a long-term process that requires persistence and patience. Don't overtraining, and don't expect to see the results too soon. Persevere and gradually increase the intensity and weight of training, and muscle growth will gradually appear.

In short, thin people need comprehensive methods to gain muscle, including scientific diet, reasonable exercise plan and adequate rest time. If you want to start muscle building training, please be sure to consult a professional fitness instructor before fitness to ensure that your training plan and posture are correct.