Warren Gatland, the Wales coach has hailed finely-tuned fitness levels as a key factor behind his side's current success.

Wales yesterday climbed into the top five of world rugby before their twin assault on the RBS 6 Nations title and grand slam glory.

A 19-12 victory over England at Twickenham on Saturday not only clinched the Triple Crown for Gatland's squad, but also helped them move above them in the International Rugby Board world rankings.

Wales are fifth behind world champions New Zealand, Australia, France and South Africa after putting themselves two home wins away from a second unbeaten Six Nations campaign of Gatland's four-year reign.

The top four countries at the end of this year will be the seeded teams at the World Cup in England in 2015.

Much has been made of the Wales players' fitness honed at punishing pre-World Cup and Six Nations training camps in Poland, and it continues to serve them well.

"I think we are pretty good, conditioning-wise," Gatland said. "I think that the fitter you get, your skills improve as well and your decision-making improves.

"I have prioritised fitness for the whole four years really, and there have been times when the players have come into a Wales camp knowing they are not really in good enough shape to take on other teams.

"The significant turning point for us was the preparation for the World Cup, when we basically hammered home the conditioning and the fitness."

World Cup semi-finalists Wales will secure Six Nations silverware if they beat Italy and principal title rivals France in Cardiff next month, and Gatland believes their Twickenham triumph cannot be understated.

"I think it is a significant result," he added. "To come through games like that does give you the self-belief, because it was a dogfight.

"We've now come through two games like that in this championship, at Twickenham and in Ireland.

"Perhaps in the past we would have capitulated [at Twickenham] or lacked that self-belief, but there is an attitude now that the players back their conditioning and never give up.

"I thought that although England played well, we put their scrum under a bit of pressure and we handled their driven lineout pretty well, too."

Scotland face a threat to their World Cup future if they do not start winning games soon. An RBS 6 Nations wooden spoon could have a daunting knock-on effect on the prospects of Andy Robinson's side reaching the knock-out stages of the next tournament in England.

Though the Scots have automatically qualified for the 2015 event, an extension of their run of defeats would put them in danger being consigned to the fourth pot of seeds.

That could leave them placed in a pool with, for example, the champions New Zealand, England and Samoa.

The draw will be made immediately after the autumn Test series later this year and will be based on the official IRB World Rankings at that time.

Between now and then, Robinson's men have a daunting fixture list with, on current form, little scope for climbing the list. After the Six Nations away games against Ireland and Italy, they head for the Southern Hemisphere in June to take on Australia along with fast-improving Fiji and Samoa. Then they are back on home soil to take on the All Blacks, South Africa and Tonga.

In spite of Sunday's 23-17 loss to France at Murrayfield, Scotland remain in 11th place in the rankings. They are currently one place above Italy, but a defeat in Rome in the probable wooden spoon decider a fortnight on Saturday could result in the sides swopping positions.

That would put them at risk of slipping outside the top 12 at the crucial cut-off point at the end of November.