GEORGE North says Wales' "savage" World Cup training camps have been even tougher than their infamous 2011 preparations.

Warren Gatland's side reaped the rewards of their lung-busting conditioning efforts when they reached the semi-finals in New Zealand four years ago.

This time round the squad has been put through their paces at high altitude in Switzerland before grafting away in the blistering heat of Qatar.

"It's been pretty savage by anyone's standards," said Northampton winger North, who could be a midfield option following Jonathan Davies' injury.

"For the boys that were here from the last World Cup to this camp, it's taken a hell of a step up.

"The heat is a stimulus, which is horrendous for the bigger guys, trying to run in it. Coming from north Wales as well, we don't get much sun up there, so it's horrible!

"It's the hardest thing I've had to do, pre-season wise. I think I've been to places that no man should be on his own.

"I've seen gremlins, I've seen different things when I've been running, but that is pre-season. We are not here for a long time, we are here for hard work and graft.

"The facilities here (in Doha) are the best I've seen in the world. Having that chance to train here and get the full reward from that has been brilliant. It's been hard, but it's been awesome."

It's not all been fitness in Qatar with the squad having to show they can execute their rugby skills when mind and limbs are tired.

North said: "Every camp is slightly different but this one has been particularly good in the sense that we are working on a conditioning base and getting that stimulus, but also while the boys are down and super tired they are getting that rugby exposure as well.

"We are doing skills while we are fatigued. While we are meant to be recovering, we are doing skills, we are doing rugby-based things, like patterns and plays, just so when we came against it on the pitch we are used to working under fatigue."

The squad is now back in Wales and will enjoy some rest before joining up again on Monday to start preparations for the first warm-up against Ireland in Cardiff on Saturday, August 8.

That is followed by a trip to Dublin on Saturday, August 29 before Gatland names his final 31 on the Monday.

The final friendly sees Italy visit the Millennium Stadium on Saturday, September 5 with Wales starting the World Cup against Uruguay on Sunday, September 20.