It's been 14 years since a woman younger than 35 has won the Pikes Peak Ascent.
Cindy O'Neill, 46, of Manitou Springs, and Nederland resident Lisa Goldsmith, 43, are expected to be at the front of the pack for Saturday's race, having finished second and third last year.
Take one glance at O'Neill's times - she ran the 13.32-mile race to the summit nearly 17 minutes faster last year than she did at age 31 - and you'll start to wonder if 41-year-old Olympic swimmer Dara Torres is in a class by herself after all.
"Occasionally, I get people thinking it's not healthy for me to be doing this," said O'Neill, who is planning to run Pikes Peak for the 13th time Saturday. "My mom and my massage therapist worry because my hormones are lessening.
"This year I was kind of bummed out and kind of starting to believe them, but then I got out there on the mountain and started training. I had some horrible runs, started feeling good again and I'm still enjoying it. I'm not listening to those people anymore."
Some anecdotal and scientific theories for women's ability to improve at distance as they age include an increased tolerance for pain, hormonal changes and improved training methods. Conclusive answers, however, are hard to come by.
"It truly is an epiphenomenon - even my medical background doesn't give me any answers," said Dr. Lisa Gidday, 48, of Littleton, who has registered to run the Ascent for the fourth time. She finished 23rd last year, improving her time by 10 minutes from her 3:45 at age 45.
"If it's not physiological, then I think it has entirely to do with the perseverance of women," she said. "They have more perseverance about life and commitment and passion as they get into their 30s and 40s. I think that would apply and maybe that's all it is. Maybe it's that phenomenon."
Sharon Greenbaum, 45, who has signed up for her 21st trek up Pikes Peak - including four Marathon round trips - offers her own theory.
"I think it depends on the person and their genetics," the Colorado Springs resident said. "I definitely don't have the genetics and I certainly can't say I've gotten better, but I've maintained and enjoyed it. I think as I've gotten older, I've valued it more."
The combination of running and power-hiking employed by most in the Ascent is appealing and also seems to ward off injuries, said Greenbaum, who puts in about 25 miles per week, including speed work and running on Barr Trail. Greenbaum, who finished 22nd out of 485 women last year, has kept her times between 3 hours and 3½ hours since running her worst time, 3:49, at age 15.
"Running can be a really jarring sport," said Greenbaum, who has stopped running flatland marathons. "I've found since the Peak race is more of a combination of hiking and jogging, I've had more longevity. ...You don't have to train or pound on the roads."
O'Neill's training habits have shifted over time, too. She doesn't log nearly as many miles as she used to and sticks to trails as much as possible.
"I think as you get older, you realize how important rest is," said O'Neill, who has also tried her hand at triathlons and cycling. "The years of mileage under your belt allow you to do that. You don't have to train as many miles. You still have the kind of base that you did because you've done it for so many years."
Though she's tuning out the doubters, O'Neill said she isn't anticipating her first Ascent win since 2000. She thinks a younger competitor, such as Bailey's Brandy Erholtz, 30, will take the title. Erholtz captured the USA Mountain Running Championship in June.
"She's really, really talented," O'Neill said. "We are getting some younger ones now with the prize money. And that's going to make it where you won't see the older people winning anymore."
Who will win this year's Ascent and Marathon is anyone's guess, though Manitou Springs' Matt Carpenter, 44, is a favorite to win the Marathon for the third consecutive year. He will not defend last year's Ascent win.
Salynda Fleury, the 22-year-old who came out of nowhere to be crowned the female Marathon champion, isn't listed in the field.
Last year's female Ascent winner, Maria Portilla, is competing in Beijing.
For O'Neill, Saturday is all about reaching the summit.
"I'm not running faster than I ever did," she said. "I'm happy that I'm staying close to my times when I was 36 and 37 years old. That's thrilling. I'm definitely not getting faster. I'm staying close, which is kind of amazing to me.