Olympic champion Jessica Ennis-Hill has said that her performances at this month's Anniversary Games in London will help her decide whether to compete at the World Championships.
The 29-year-old did not compete in 2014, after giving birth to her first child, and she missed the previous World Championships in Moscow two years ago through injury.
"I'm definitely getting closer to where I need to be," she told BBC Sport. "In my mind I know what shape I need to be in to compete and contend for a medal at the Worlds and I have a target for this weekend.
"I hope to have the performances I am looking for in London and can go and compete for a medal in Beijing. Or, I hope that I know on Saturday night that I am not going to be in a position to compete and I don't push on to the Worlds when I'm not quite ready.
"Nothing is guaranteed in sport but I don't want to travel all that way and not medal or perform to my best. If I'm not quite ready the best thing would be to have a break and get ready for winter training."
Ennis-Hill won gold in the heptathlon at the 2009 World Championships.