You got me thinking... TexasPumpkin is definitely right.  Here's a resource to check out - http://running.about.com/od/howtorun/tp/runningform.htm

Forty years old here with three kids.  I am about twenty pounds overweight.  I started the program in June and yesterday I ran the first mile of my life.  I haven't lost a pound but I'm not too concerned with that yet.  I am doing the program with my ten year old daughter.  Sometimes that makes it harder (finding time we're both available, dealing with her ten year old moods) but for the most part, it's very motivating.  I know if I quit, she's done too.  This is at least the third time I've started the program but it's the furthest I've ever gotten.  I feel great.  You can definitely do it.  Everytime I know I have to run a longer interval, I'm worried I won't be able to do it.  It's not always pretty but we almost always finish it.