MMRCer Jack has a talent for finding fascinating running stories, like this New York Times article about ultrarunner Diane van Deren‘s upcoming speed ascent of Argentina’s Mount Aconcagua, the highest summit in the Western hemisphere at 22,841 feet. While this is an amazing feat in itself, several elements make it even more remarkable.

Van Deren, profiled by the Times at length last July, formerly used running to stave off grand mal seizures—often running for hours and even overnight. She eventually underwent a lobectomy that removed a kiwi-sized portion of her brain to cure them. Surgery worked as planned, but resulted in a loss of memory and organizational skills—it’s nearly impossible for van Deren to remember where she parked her car, read maps, or follow trail directions, for instance. The upside is that van Deren now finds that she can run without worrying about time and distance. Researchers at Mayo Clinic want to monitor her performance during the expedition to determine if her surgery has actually helped her to be a better runner. To aid in their research, van Deren agreed to do what she had never done before: run on a treadmill. Here’s what they learned about her:

“Her maximal oxygen uptake, one way to measure fitness level, Johnson said, was about twice the average for a woman her age. She could sustain heart rates of 97 percent of her maximum for long periods. Her lung surface area is about one and a half times the average size. Her muscle efficiency was much better than normal. Her ‘peak aerobic capacity,’ Johnson said, is well above what would be normal for a 20-year-old, never mind someone about to turn 50.”

Follow the North Face Aconcagua Ultra expedition, which gets underway on Friday, January 22. More updates can be found at the Mayo Clinic blog and via Twitter.