Even world class performers can benefit from walk breaks.
Here is the start, there is the finish line. Between that, you have to run.
The marathon is a competition between your will and your possibilities
Marathon training doesn't have to be a grind. By running for about 30 minutes two times a week, and by gradually increasing the length of a third weekly run-the long run-anyone can finish a marathon.
Our bodies crave exercise, and reward us in so many ways when we do so.
We have a no puke rule. The purpose is performance, not puking.