is an 11 minute mile realistic?

Hmmm.
http://well.blogs.nytimes.com/2011/05/23/on-your-marks-get-set-measure-heart-health/

From the study data, Dr. Berry calculated that a man in his 50s who can run a mile in 8 minutes or less, or a woman who can do it in 9 minutes or less, shows a high level of fitness. A 9-minute mile for a man and 10:30 for a woman are signs of moderate fitness; men who can’t run better than a 10-minute mile, and women slower than 12 minutes, fall into the low-fitness category.

Guess I fall into the low-fitness category, c'mon a 20 minute mile. Pathetic, I know. I can do better. Exercise, movement, it's the only way to combat aging according to, well, everyone.

And:

Even so, Dr. Church noted that most of the health benefits of exercise come with moving from low fitness to moderate fitness, and the challenge is finding a way to communicate with and motivate people in the low-fitness category.

“You know whether you’re in the unfit category,” he said. “If you’re physically inactive, if you sit 18 hours a day, if you get exhausted walking up a flight of stairs. If you’ve got a choice between walking two blocks or taking a taxi and you wait 20 minutes to take a taxi, you’re unfit.”

Dr. Berry agreed that mile-time benchmarks might not be good indicators for every individual, given that some highly fit people have physical limitations that prevent them from running fast. The larger issue, he said, is that most people don’t have a clear sense of where they fall on the fitness spectrum, and don’t appreciate the risks that poor fitness poses for overall health.

Even people who take regular walks three times a week may have an inflated sense of their level of fitness, he said, adding, “You’re meeting the guidelines for physical activity, but you’re not necessarily fit.”

While modest levels of exercise are better than nothing, he went on, “getting off the couch is the first step, but vigorous activity has a much more dramatic effect on fitness level.”