It is grueling enough to swim 2.4 miles, bike 112 miles and run 26.2 miles, but imagine doing all of that when you can only see a blur of light ahead of you.
Kristina Ament, a 52-year-old federal prosecutor, has completed four Ironman triathlons under those exact conditions because of her Leber congenital amaurosis, a degenerative disease that causes acute vision loss.
Now the Alexandria, Virginia, resident is training for October's world championship in Kailua-Kona, Hawaii, as one of five winners of the Ironman lottery for physically challenged athletes.
Organizers could not provide an exact number of visually impaired athletes who have completed the Ironman world championship, but they say dozens have competed in the 32 years since a category was created for the disabled. They must complete the three endurance events in under 17 hours, just like everyone else.
One visually impaired athlete, Charles Plaskon, made it to the finish line in 14 hours and 49 minutes in 2007 with the help of a guide.
Like Plaskon, Ament relies on other athletes to guide her through the competition. Every stroke or stride she takes is done while tethered at the waist or arm to someone who can see. It means Ament must find a rhythm with her guide, create a game plan ahead of time to stay in sync.
"The guide usually describes the course in advance, saying, for instance, it's a square. It's going to be all left-hand turns. It's about this many yards to the first buoy; this many yards to the next," Ament said.
"If we get a system going and I know the course well enough, they can just tap my shoulder when its time to turn."
It is crucial for Ament to have a system down pat with her guide, especially in the water, where lifting their heads up to talk could slow them down, she said.
"The swimming is really difficult for a lot of blind athletes, because it takes away hearing, which is the sense you rely on the most to get an input," she said. "For me, learning to swim in open water was a challenge for that reason; it's kind of like you're suddenly in massive sensory deprivation mode."
Ament has also struggled to find other women who ride tandem bikes or who are willing to help her transport the heavy, cumbersome set of wheels. Anne Thilges, who has guided Ament in two races and will join her in Hawaii, said the double-seated bike can be hard to maneuver around corners, but they've gotten the hang of it.
Transitioning from one event to the next often presents a big challenge, too. For Thilges, it's a matter of keeping track of each other's moves so they don't get tangled in the tether.
"The transition time can wildly vary," Ament said, "depending on how far you have to run, what the race conditions are, whether you're wearing a wet suit."
In her best time, Ament made it to the finish line in 13 hours 47 minutes at an Ironman in Panama City, Fla. But she considers her best-executed race to be the one she completed in 14 hours and three minutes in Arizona.
"I hadn't had any injuries, and I'd been doing a lot of running and a fair amount of cycling, over 90 miles," Ament said. "Things just really pulled together for me that day."
In a typical week, Ament bikes for 90 minutes and runs about seven miles a day, extending the distance to up to 20 miles on the weekend.
Getting to Hawaii was unimaginable when Ament first started watching the Ironman World Championships on TV in 1987.
At the time, she said she was an overweight law student with little desire to run, swim or bike. It wasn't until Ament graduated and began clerking for a judge who had a penchant for exercise that she started working out.
When she moved to Washington years later, Ament became a competitive rower and picked up running, all the while losing more of her eyesight. By the time Ament completed her first triathlon in 2010, she had no "useful vision."
"I still have light and shadow perception," Ament said. "It's sort of like running drunk."
On Oct. 11, Ament will compete alongside more than 2,000 athletes in Kona, where 45 mph crosswinds and 90-plus-degree temperatures add an extra layer difficulty. She is worried about biking in such windy conditions and competing in the heat. But the excitement beats all concerns.
"I'm looking forward to so many things, just the idea of being at an event where the best triathletes in the world are coming together," Ament said.
"Even though people are nervous and competitive, everybody is supportive of each other."