I'm a 13 year old girl, 5' 1", 95 pounds, 22 inch waist and 32 inch hips. It's nearing the end of track season now (I'm a long/middle distance track runner and a cross country runner), and I never noticed how skinny I was before. I'm starting to run 30 miles a week in order to build my base for XC season in the fall, and I've got a resting heart rate of 48 bpm.

I was just wondering whether I'm too skinny to be healthy, I feel perfectly fine all the time, but I have a stomach like one of those female body builders with 2% body fat on steroids... help?

Hello I went on this website Centers for Disease Control and Prevention and worked out your BMI, here are the results

Information Entered
Age: 13 years 0 months Sex: Girl
Birth Date: 1994 Height: 5 feet 1 inch(es)
Date of Measurement: 2007 Weight: 95 pounds

Results
Based on the height and weight entered, the BMI is 17.9, placing the BMI-for-age at the 38th percentile for girls aged 13 years 0 months. This teen has a healthy weight.

Don't worry just be yourself and you'll put on some more adipose tissue (fat) as you get older and your hormones kick in. Perhaps up your calorie intake if you are increasing your running - but just ask your coach they'll know better than me.

It's great you have such a healthy hobby keep it up!