As a postscript, it's interesting to note that TPP has now changed her tune. She has decided that walking breaks are no longer the way to do your best marathon or go faster as she has previously claimed. Now she says "The main benefit of the run-walk method is that it eases your body into exercise, makes marathon training less grueling and gives muscles time to recover, reducing the risk of injury. Walk breaks are an ideal way for new runners and older, less fit and overweight people to take part in a sport that would otherwise be off limits.
"The downside is that just as you are out on the marathon course about 50 percent longer than the average runner, your training time is much longer, too — four and five hours a weekend for long runs.
In other words, she is agreeing with what i said all along.