Out of Shape

I've been consistantly running with some ladies in my neighborhood. They are ten years younger and a lot thinner than I. I just want to say that I feel like throwing up when I get home. Is that normal? Okay, I'm a lot more out of shape than I thought. Before I had the twins I was running three miles a day. Since they came into my life I would go an exercise like one day every two weeks. I guess I wasn't going very fast either. I have to say it is a struggle to pull myself out of bed to go jogging at 6:30 every morning. Especially when I feel so yucky afterwards. Where's that runners high? I guess that will kick in after a month or so. Can't wait for that to happen.