Originally Posted by Mr. Flopnuts
Whether it's faster, longer, or both, always be ready to die when you step off. That's what I did, and it worked wonders for my endurance and my speed. It also helped the **** out of my self image. May not be an issue for you, but you can never feel too good about yourself and your accomplishments.
Eventually, you'll hit a point where that is virtually impossible. Generally, that's about the time you can run 6+ miles without walking. If you find your pace, you'll get to six...seven...eight...and feel like you can just keep going forever...and that's because you can. You don't have to feel like trash afterwards in order to have a great workout, IMO.