New York - Caroline Wozniacki always feels confident she can outrun her opponent on the tennis court.
The former world No. 1 believes that with a bit more training, she can cover 42km.
Wozniacki plans to play a full tournament schedule this autumn while fitting in time to train for the New York City Marathon.
She typically runs for 30-40 minutes a day as part of workouts for tennis, and hopes that one longer session per week of an hour or more can get her through the 2 November race.
And, no, she's not seeking this challenge in an attempt to distract herself from her personal life, Wozniacki insisted.
Golfer Rory McIlroy broke off their engagement in late May, less than a month before Wozniacki decided to run a marathon.
"Tennis helped me just get through the tough times," Wozniacki said in Manhattan on Thursday.
"Now I'm just feeling happy and I wanted to do something good for others.
"I think that this had nothing really to do with my personal life. It was something I was passionate about."
She had long wanted to run a marathon, and looking at the tournament schedule, she determined it was doable.
About a week before Wimbledon, she asked her manager to look up charities she could raise money for.
Wozniacki will represent Team for Kids, which helps fund NYC Marathon organizer New York Road Runners' youth programs.
"People ask me, 'Why don't you just run a 5K or 10K?' I'm like, 'Well, I do that all the time, so it wouldn't really be a challenge,'" she said.
"This is really something I need to put my mind to."
She's never entered a road race, and the longest distance she's ever run is 18km, which is a bit less than a half-marathon.
Wozniacki hopes to qualify for the WTA Finals, which run from 20-26 October in Singapore, ending just a week before the marathon.
She's 17th in the standings, though, with only the top eight players taking part.