To grow big muscles, you will need to engage in regular resistance training, such as weightlifting or bodyweight exercises. It is also important to eat a balanced diet that provides your body with the necessary nutrients to support muscle growth. This should include plenty of protein, as well as carbohydrates and healthy fats. Additionally, getting enough rest and sleep is essential for muscle growth, as this is when the body repairs and rebuilds damaged muscle tissue. It is also important to listen to your body and avoid overtraining, as this can lead to injuries and hinder muscle growth.