Sarah Jo answered 6/1/2010 Am I A Fat Gymnast At 5'1 And 120lbs? WOW! 120 for a 16 year old!!! That's amazing!! You are underweight:)) I am 11 weigh 70 IBs. And am 5/3 already!! You are the perfect height and weight. You are beautiful either way!! It's not how you look in gymnastics, it's how you feel!