Practicing chest muscles has nothing to do with being fat or thin. People who are particularly thin will practice lines more easily. However, the chest muscles trained by people with thin bodies are obviously plate-shaped and not full, but the back muscles are still very beautiful. Then the exercise method is mainly through gradually strengthening push-ups, dumbbell barbell bench press or other equipment. Practice more than three to five groups every day, and basically there will be obvious lines in a month or so.