hair question..

I noticed something the other day, after almost 5 months of my hair falling out it's finally stopped. I'm sure that's due to the pregnancy and higher intake of calories, but I just wonder why it was falling out in the first place.

Yes, I was dieting and running, but I was still getting plenty of calories and eating a pretty well rounded diet. I was on the border of looking for a hair loss shampoo it was seriously falling out by the handful every morning. Luckily my hair never looked thin, or weird, it stayed healthy looking, my house on the other hand looked like there was some crazy long haired dog living there that was shedding like crazy.

Has anyone else had a problem like this when they were training for a half marathon, or losing weight?