It's the race that will kill you and still earn you no respect. It doesn't have an Olympic equivalent; it doesn't even have a name of its own. Yet runners sprint to sign up for it in far greater numbers than its prestigious sibling, the marathon.
First-timers tend to think a grueling 13.1 miles shouldn't be called "half" of anything, while veterans think loping to the finish line in an hour and a half makes for an easygoing Sunday morning.
The half's appeal, they say, is that it welcomes both groups and everyone in between.
The half-marathon is America's new favorite running distance with more and more races being offered. Five times as many people finished half-marathons across the country in 2011 than in 1990, according to Runner's World Magazine.
Enthusiasts who think the race deserves its own name have started an effort to rename it the Pikermi, after the Greek town halfway along the 26.2-mile span between Athens and Marathon. But the word "marathon" carries some weight as well.
"Psychologically, since it's called a half-marathon and because 99 percent of normal people wouldn't attempt it, it sounds like a huge achievement -- something you talk about when you go to the office on Monday morning," said Jeff Peterson, a competitive half-marathon racer from San Anselmo, Calif.
The half-marathon is increasingly a female-dominated race. In 2011, 59 percent of all half-marathon finishers were women. At the Nike Women's marathon and half-marathon hosted in San Francisco every fall, each finisher's reward is a Tiffany necklace, handed out at the finish line by San Francisco firefighters dressed in sharp suits.
"My wife coaches a lot of women who were pregnant, had a kid, and started to run to get fit again," said Peterson, whose wife is also a competitive runner. "They get into it, they want to race, and a half-marathon is the best distance to start because you feel the finish line the whole time, compared to 26 miles, which just sounds mammoth."
If a half-marathon were too easy, finishing one wouldn't have any reward, said Kristin Tarr, 29, who has been running half-marathons since 2008, but still treats the distance with respect.
"Just because it's not the full doesn't mean it's not challenging. It's very challenging," Tarr said. "You can't just walk out your door and say you're going to run 13 miles. You can't. I mean, you can, but you're going to pay for it. It gives you something to train for that feels manageable but is still a big accomplishment."