Wales in better shape than 2011
Wales are in a tough group with hosts England, two-time champions Australia, Fiji and Uruguay..
After summer training camps in Switzerland and Qatar, Wales lost 35-21 to Ireland in a warm-up match last week.
However, Warburton believes the fitness levels of his squad are higher than they were before the 2011 World Cup.
"We are in a better place physically," the 26-year-old flank told reporters.
"We probably got to the fitness levels that we were at in 2011 a couple of weeks ago, and we've got a nice two-week block now until Ireland."
Wales, who finished fourth in the 2011 World Cup, after losing to France in the semifinals, play Ireland again in Dublin on August 29, before coach Warren Gatland names his final 31-man squad.
They finished third in this year's Six Nations, behind Ireland and England on points difference.
"I thought we were playing some great stuff towards the end of the Six Nations," Warburton said.
"We felt very comfortable playing together, so it's about getting that cohesion back by the time the World Cup starts."
They begin their campaign against Uruguay in Cardiff on September 20 at the Millennium Stadium.
Source: (Reuters)
