SCOTT SIMON, HOST:
Tomorrow morning, a woman from North Carolina will run her 16th marathon. Now, that's impressive; it's also remarkable when you consider that she's 92 years old. In fact, if Harriette Thompson completes all 26.2 miles tomorrow in San Diego, she will become the Guinness World Record holder for the oldest woman to finish a marathon. Duncan McFadyen of member station WFAE has this profile.
DUNCAN MCFADYEN, BYLINE: Harriette Thompson is not competitive and doesn't really consider herself an athlete. She's always kept fit and runs a few miles most days around the retirement community she lives at in Charlotte, N.C. She doesn't eat a special diet and didn't run her first marathon until she was 76. Even then, she showed up expecting to walk the 26.2 miles but...
HARRIETTE THOMPSON: When I started, everybody was running, so I decided well, I guess I'll run, too. And it didn't seem - at that time, it wasn't so bad.
MCFADYEN: Sixteen years later, she's completed the San Diego Rock 'n' Roll Marathon 15 times. She says her secret is mental rather than physical. Thompson taps into that discipline from her time as a concert pianist when she had to memorize and perform long, complicated pieces of music. Now, some of that music helps her to stay on track.
THOMPSON: I usually think of Chopin Etudes - the ones that are technically difficult because usually they're pretty fast (laughter) and that makes me - stimulates me to go a little bit faster. And also, it helps me pass the time.
MCFADYEN: He she is playing one of her favorites on a concert grand piano in her living room.
(SOUNDBITE OF PIANO)
MCFADYEN: Music isn't the only thing on her mind when she runs. Thompson does marathons to raise money for the Leukemia and Lymphoma Society in memory of friends and relatives who've died of cancer.
THOMPSON: Everybody in my family has died of cancer; it's sort of in our genes. Just recently in January, my husband died of cancer. And my husband's brother died of leukemia, and he was young, and I just miss them all.
MCFADYEN: She herself is a cancer survivor. In 2013, she skipped the San Diego Marathon because of surgery for mouth cancer. Last year, she ran the race a few weeks after completing radiation treatments for cancer in her leg. She admits it still hurts when she runs, but she doesn't let that slow her down.
THOMPSON: No, no - my leg bothers me some, but sometimes I don't feel it.
MCFADYEN: As for setting a world record this year, well, Thompson says that's all her son's idea.
THOMPSON: I've never even seen the book or the record, but that's nice if they want to put me in.
MCFADYEN: She actually made it into the books last year at 91. She finished in just over seven hours, beating the previous marathon record for a woman 90 or older by more than an hour and a half.
THOMPSON: I was surrounded by microphones, reporters and (laughter) so I thought, well, it pays to be 90 (laughter).
MCFADYEN: Thompson says over the years, her family and friends have tried to figure out why she keeps going back to the San Diego Marathon, and sometimes she wonders herself.
THOMPSON: I guess it's just a bad habit (laughter). I don't know really. It's just that I want to do it.
MCFADYEN: She says she always worries she may not be able to finish. And if that happens tomorrow, she won't let it drag her down. After all, she can try again next year. For NPR News, I'm Duncan McFadyen in Charlotte. Transcript provided by NPR, Copyright NPR.