http://well.blogs.nytimes.com/2010/11/04/born-to-run-the-marathon/

It would be absurd if trout were at high risk for swimming
injuries or 90 percent of blue jays tore their rotator cuffs from flying. Yet
humans, who only had their feet for transportation for most of their existence,
somehow arrived in the 21st century broken on delivery. Geronimo used to outrun
cavalry horses and say, “You can only count on your legs. They’re your only
friends.” So why are doctors telling me just the opposite?

And then I saw Derartu Tulu.

When she entered last year’s New York City marathon, Ms. Tulu was a 37-year-old
has-been from Ethiopia who hadn’t won a marathon in eight years. Months earlier,
she’d decided to retire. She hadn’t competed for two years after nearly dying in
childbirth and was coming to realize she’d never regain the form that sped her
to an Olympic gold medal nearly two decades before. But the limits of her aging
body were complicated by the demands of a tender heart; in addition to her own
two children, she’d adopted four orphans, and one last payday could guarantee
her family’s security for a long time. She decided to go for it.

Unfortunately, so did the most formidable female marathoner in history: Paula
Radcliffe, the world-record holder and three-time New York City champion. “Lean
and mean,” the race announcers said in awe as they watched Ms. Radcliffe rocket
off the starting line. “All the other athletes are so intimidated by this great
champion. She’s the sharp end of this spear.”

But at mile 22 something strange happened, followed by something even stranger.
Ms. Radcliffe grimaced and fell back. Her left hamstring had seized. It was the
chance of a lifetime for Ms. Tulu — and she blew it. Instead of blazing toward
the finish, she let the lead pack pass while she stopped and waited for Ms.
Radcliffe.

“Come on,” she urged the lean, mean spear tip. “We can do it.”

Ms. Radcliffe tried, but her hamstring wouldn’t release. Ms. Tulu finally set
off on her own. Somehow, she caught back up with the lead back, and then the
under-underdog blew past in the final quarter-mile to snap the tape. It’s among
the most awe-inspiring performances I’ve ever seen, and to this day, I still
don’t understand exactly what happened.

The best I can come up with is this: Maybe it wasn’t a coincidence that one of
the most compassionate people on the streets that day was also the most
competitive. The greatness of spirit which urged her to watch for every
faltering orphan, to keep the pack together, also gave her the strength to lead
it. At its finest and most time-tested, after all, running was never a solitary
pursuit.