Caroline Wozniacki's decline from world No.1 to outside the top ten was in part caused by a gruelling schedule of promotional work, the Dane suggested on Monday.
Wozniacki finished 2010 and last year as No.1, earning her a bevy of lucrative sponsorship deals, but she is now No.11 after winning only the Korea Open this season and exiting Wimbledon and the US Open in the first round.
"Sometimes people don't realise how much attention, how much media, how much off-court stuff there is when you're at the top of the women's game and sometimes it's just tough to get everything together and your body just says 'I can't any more'," Wozniacki said when asked about her decline.
Wozniacki said that constant promotional appearances mean much less practice time at major tournaments, which can damage a player's game.
"Other players maybe have the opportunity to practice four hours a day, whereas you maybe have one and a half, but you need to make the most of those one and a half hours," she said.
"At some point you're going to be a little bit tired and it's going to affect your work."
Despite the compromises involved in doing a lot of promotional work, Wozniacki said she had no intention of giving up any of her contracts, saying that she felt the need to make the most of a brief career in the spotlight.
"Very few of the players actually have a lot of sponsors off the court and I would like to take advantage of that because the career of a tennis player is short," she said.
Wozniacki has a bye for the first round of the Kremlin Cup in Moscow and will face either former French Open champion Francesca Schiavone or Poland's Urszula Radwanska in the second round.