You may exercise less, or your skeleton is smaller. This height should be at least 95 in bust, 55 in thigh and 0/00 in hip. Waist and calf circumference can be maintained, and it is best to increase the arm by 2 to 3 cm. Go to the gym to exercise. If you have narrow shoulders, I suggest you do more barbell push. According to our fitness standards, your height, chest circumference 100 and arms 34~36 are normal. Before doing exercise, the chest circumference was 105 and the height was 183. At that time, I was 70kg and my skeleton was relatively large.