Marathons are for optimists.
On Sunday, two of those practitioners of hope will be 27-year-old Amanda McGrory, a champion the last time the New York City race was run two years ago, and Tatyana McFadden, 24, attempting to complete a "grand slam" of winning London, Boston, Chicago and New York all in the same year.
McGrory will be in the pink racing wheelchair, McFadden in the purple.
What's so foreboding about 26.2 miles compared with these back stories?
"I was a really, really high-energy child," McGrory said. "I woke up one day when I was 5 and couldn't walk, couldn't ride my bike, couldn't run around."
McGrory, paralyzed from the waist down, was diagnosed with a rare viral condition.
McFadden was born with spina bifida and abandoned in a Russian orphanage with her spine protruding through the skin, expected to live only weeks. She was 6, still critically ill, when an official in the first George Bush administration visited the orphanage on an assignment to distribute aid to the disabled in St. Petersburg.
"She was crawling on the floor," said the official, Deborah McFadden. "She didn't have a wheelchair. But she could flip and walk on her hands, and she came over and started talking to me. In Russian."
Smitten, the elder McFadden worked to get Tatyana medical help. After repeated visits, she adopted her, brought her home to suburban Baltimore and signed her up for swimming, gymnastics and, by the time she was 7, wheelchair races.
"She kept saying [what sounded like] 'Ya sma, ya sma,' " Tatyana's mother said. "Which, in Russian, means, 'I can do it myself.' "
At about that time, McGrory, growing up 45 minutes from Philadelphia, had found wheelchair sports through her own mother's exhaustive searches. "My first race was when I was 5," McGrory said. "I got my first racing wheelchair when I was 11."
Regional competitions brought the two together on a regular basis entering their teenage years. Both played wheelchair basketball and both went to sports camps sponsored by the University of Illinois, which runs the nation's top intercollegiate wheelchair sports program.
Both now are studying at Illinois. McGrory graduated with a psychology degree in 2010 and is returning for graduate work. McFadden's major is human development. Both represent Illinois' powerhouse wheelchair track and field team. Both have won multiple Paralympic medals.
"I just wanted to gain strength, to gain independence, but wheelchair racing, as soon as I got into it, I knew it was the sport for me," McFadden said.
The same for McGrory, who, before she was disabled, "never met another child, or anyone, with a disability." Finding wheelchair sports brought "a different kind of relationship, because what I was going through, my [able-bodied] friends couldn't relate to."
For years, McGrory's father refused to buy her a pink racing chair -- "too girlie; everybody will make fun of you" -- so her rebellion as a college freshman was obtaining the first of five pink chairs. McFadden always has raced in purple. Nobody is making fun of either.