Mainting a healthy weight... when you're underweight

[jleigh]

I'm a pretty tiny person, 5'1" and weigh 95 lbs. I want to get on my bike a few times a week but I don't know how far I should be going.

It is my understanding that you can OVERdo it, and as I am a bit underweight at this time I want to learn how to eat so I can still ride to my hearts desire without risking my health...

Suggestions??

Also going to add, and hoping no one 'throws' anything at me. I eat well throughout the day, maybe not the best foods (which is why I am here), but I am eating. My last check up with Dr showed SLIGHTLY elevated thyroid levels but nothing to warrant the need for medications.