Originally Posted by Urbanmule
I used the link, the last 5k I ran was 31'46. The link says I should run the half at an 11'13... which to me seems really slow, I could go out tomorrow and run that and not be tired.
How long ago was the 5k? As you're still new to running, you will see a great deal of improvement in a short time. (Won't last forever)
This is one of the reasons I like training by heart rate-you run at the same rate and your pace will speed up on it's own as your fitness improves.
A half marathon pace will feel easy through the first part of the run. Feeling good at 6 doesn't mean you'll feel that way at 13.1.