Chau Smith ran her first 5K marathon in 1995 in Kansas City, when she was 48.
She fought through hay fever and a sinus infection and nearly passed out. But she completed the race.
“They (had) to put the oxygen mask on me," Smith told NBC News. "But I feel OK about half an hour later. So Michael (her husband) drove me home to Independence from Kansas City. I said, 'Hey, Michael, I want to do a 10K.' And he said, 'Chau, you almost died today. What are you talking about?' And three months later, I show him. I did a half-marathon and never look back.”
Since then, she has run about 70 marathons across the world, including the 2013 Boston Marathon, as well as seven races on seven continents in 2014.
Her biggest feat was completing the Triple 7 Quest: seven marathons on seven continents in seven days.
She ran marathons in Perth, Australia; Singapore; Cairo; Amsterdam; Garden City, New York; Punta Arenas, Chile; and King George Island, Antarctica, between Jan. 25 and 31, 26.2 miles each day.
She was joined by nine other people.
"It's just amazing what she did," Steve Hibbs, who helped organize the trip, told NBC News. "If there's anything to describe her, it's 'result.' She wants to prove to herself that anybody of any age can go out and run and accomplish this type of feat."
She almost didn’t get to participate in one of her favorite races in Cairo.
A connecting flight from Singapore was delayed and the team landed with only minutes to change and prepare before the race started.
"We have 10 minutes to go up to our rooms to change and don't unpack," Smith told CNN. "The key wasn't working for my room. I almost used up my 10 minutes. I was crying."
She ended up completing the race in 5 hours and 51 minutes, her best time of all seven events.
Her husband was apprehensive about the plan at first.
"Well, I know after 30-something years of marriage, I don't tell her she can't do anything," Michael Smith told NBC News. "I was very skeptical, because the potential for injury for some kind of adventure like this is very high and I didn't want to see her injured at 70 and then cut short her running career."
How did she do it?
"I always try to train in my mind the good things. So even when I'm really in pain, I'm able to think about something else positive," she told NBC News. "So you don't think about, 'Oh, my God, it hurts so bad.' You just think about maybe the waterfalls, the streams and the lake."