You can do this...you can sooooo do this. I have always been active, but I just started running a few years ago in order to do an adventure race with my DH. The key is to start slowly. Use a walk jog combo. Make sure you have good shoes. START SLOWLY.....

The breathing is very different from cycling, so just be patient, it will come.

I just started a running group at my school in January and we just did a 5k together last Saturday. Pop up to last week's running thread and check out the picture of me with my friend Jackie. She never, never thought she would be able to run a 5k. Never in a million years. She is healthier and happier and she is losing weight. She uses the spark diet site.

I do agree with a couple of the other folks here, I think your caloric intake is too low. Just my 2 cents.