The 29-year-old won Olympic gold in Athens and Beijing and admits the strain of training over the years has taken its toll.

Isinbayeva is gunning for a third straight gold in London this summer and she concedes that competing is a lot more enjoyable than the training.

"When I'm on the track, I always think, oh my goodness it's so easy. Why can't it be all the time the same. But once I get off the podium, I was like 'oh, I'm too tired for the training'," she told the Laureus website.

"I decide that another two years and then I will retire. Training becomes difficult...every year the body is getting old it becomes harder and harder to prepare for the competition. I enjoy competition more than training."

Competitor

Isinbayeva believes her hardest opponent in London will be herself on the back of winning the World Indoor Championships in Istanbul last month.

"In London, my main competitors will be myself, because I know how high I can jump and I know that height is almost impossible for my rivals," she continued.

"My coach says that my potential is 5.10 and higher, so that right now and with my present preparation, I am able to jump 5.10.

"I am not worrying about the Olympics. I am confident because I know that right now everything is fine in my life."