I am 5'4'' at the most and a small frame. My goal is to 125 lbs but if I made it to 130 I would be happy. I think that 130 lbs for a medium frame at 5'8'' is a bit thin. I am not a fan of skinny. I think that you should find out what you should weigh at your heighth and age. However, I believe that your body has already told you that answer.