World champion Yang Jiayu faces challenges from both her rivals and from the hot weather in her defense of the 20km race walk title at the Doha world championships.

The 23-year-old who arrived here on Sunday finished a training session on Tuesday night in a neighborhood close to her hotel.

"When I arrived here yesterday, I felt it was really hot and humid. It took so much energy to finish my first training session. But I am adapting," said Yang, who will begin her competition around midnight on Sunday, two years after she clinched her first world title in 1:26:18 in London.

"My rivals and I will compete under the same conditions, so I will just focus on my own performance," she said.

Yang's coach Zhang Fuxin admitted that his athletes need to put in extra efforts to prepare for the race.

"This is a situation we have come across for the first time, the hot weather and the late competition time," he said.

"We need to adjust our strategy in the race and finish with the best result we can," Zhang added.

Yang's teammate Liang Rui set her priority on finishing the competition which is scheduled at 23:30 on Saturday.

"My first goal is to finish the race," she said. "I plan to start slowly and see what I can do after 40km."