The Empire State of Mind singer's brother Cole Cook convinced her to take part in the annual race after signing up to pound the pavements for the 26.2-mile (42.2-kilometre) run on 1 November (15).

Keys will be raising money for her HIV and AIDS support charity Keep a Child Alive and she has decided to document her marathon preparation in a new blog for

In her first post, Alicia confesses she initially laughed at the idea of taking part in the annual race, eight years after she completed her first marathon in Greece in 2007. She quickly had a change of heart and now she has adopted "why not?" as her new life slogan.

"A few months ago, I was working out and minding my own business, and my brother came over to me and said, 'Why don't you run the New York City marathon with me this year?'" she recalls. "My first instinct was to say, 'HELL NO!' LOL (laugh out loud). But then I thought, This is my city, so why not?

"I thought about all the times I rode a train through the boroughs or drove through the boroughs, and it occurred to me that I've never run through the five boroughs. So why not? In fact, this is my new slogan: AND WHY NOT?

"I'm all about breaking mental boundaries, and training for a marathon falls right into the Jedi mind-training I need."

The mother of two goes on to detail the new schedule she has adopted to fit in her training, revealing she wakes up at 5.30am to meditate. She then takes care of her young boys and works out while listening to audiobooks, all before starting her working day at 11am.

"Believe me, I never thought I'd be this person either," she continues. "You know what I mean - the 'early-morning-schedule' person. I always thought I was one of those people who was lucky if I could just get up, get dressed, and get out the door on time. But somehow, I'm into it. Getting up early to take care of myself physically and mentally sharpens my focus, my dedication, and my clarity."

But, for all Alicia's training, she admits she is nervous about tackling the marathon. She signs off by writing, "Pray for me, y'all, because these runs are kicking my a**!"

Alicia isn't the only celebrity preparing for the New York City Marathon - actor Ethan Hawke and his wife Ryan will also be running for the first time, raising cash for homeless and addiction charity The Doe Fund.