The 34-year-old winger finds the sprints the toughest task of all as the double winners get back to work at their Carrington base.

"Long distance running gets easier as you get older," said Giggs. "It is just the quicker stuff that is quite hard.

"We started by seeing where our fitness is at and the treadmill test is quite hard.

"That will start to build things up. I'm not really looking forward to it but when you've done it all before, you just use your experience to get through it."

Giggs, back from a break in Portugal, is still savouring United's triumphant campaign last season when they won the Champions League and retained the Barclays Premier League title.

He marked a record-breaking 759th appearance for the club by scoring from the spot in the dramatic shootout victory against Chelsea.

It was the second time Giggs had lifted the European Cup and he added on www.manutd.com: "Obviously, last season ended brilliantly for the team and for myself.

"Although I am not looking forward to pre-season training, it is good to be back."

Meanwhile, United are insisting no decision has yet been made as to whether Cristiano Ronaldo will need surgery on his right ankle.

Reports this morning suggested the Portugal winger could be out for up to six weeks.

But United, who issued a statement last night about Ronaldo's injury, are baffled by those comments.

A club spokesman reiterated: "Procedures are in place to seek specialist advice, in order to finalise the treatment plan as soon as possible."

Should it be decided an operation is required, it could have a major impact over the Madeira-born winger's fitness for the start of the new season.

That in turn may determine how far Real Madrid are willing to push their attempts to lure him away from Old Trafford.

Ronaldo is not due back in England for another fortnight and manager Sir Alex Ferguson is yet to speak to him about the large number of statements from Madrid - which went unchecked by the player - during Euro 2008.

Eventually, United grew so sick of Real's advances that they reported the matter to FIFA, although the world governing body subsequently rejected it.