Armstrong fit for Tour Down Under

American Lance Armstrong has arrived for next week's Tour Down Under declaring he is in the best shape of his life at the start of a season.

The seven-time Tour de France champion played down ambitions for his return to professional cycling in the Australian tour, but hinted he was in arguably the best form of his career, for this time of the year.

"Considering other Januaries, it is probably ahead of what it would have been in other years," Armstrong told The Sydney Morning Herald upon his arrival late Sunday.

"But I have been training a lot earlier than the previous years as well. I am optimistic. I feel good."

The Texan cycling great said he was feeling the anticipation over his return to racing, which will have him competing in the Tour de France in July at the age of 37.

"It is hard to compare because it has been such a long break and it has been the longest break I have had," he said.

"It's both nervousness and excitement. I am excited to be here."

Armstrong will race with his Astana teammates for the first time on Sunday in the Down Under Classic criterium warm-up in Adelaide, and said he wanted to use the tour to re-adapt to racing after coming out of retirement.

"I just don't want to get clobbered too bad. That is my main motivation for training hard," he said.

"I don't have any illusions of grandeur. I hope I get in the race and get re-acclimatised to the tempo and the speed and what it is like to be around 200 guys in a fast-moving group, and we will see."

Armstrong's arrival in Australia via Sydney ended days of speculation as to his travel plans, which organisers had tried to keep secret.

Given the extraordinary interest surrounding his comeback to elite cycling, organisers said they are taking extra security measures to protect Armstrong during his time in Adelaide.

Armstrong has dedicated the Tour Down Under not only to his comeback but his anti-cancer fight through the Lance Armstrong Foundation, which was formed in 1997, one year after Armstrong was diagnosed with testicular cancer.

He successfully battled the cancer in 1996, retired from riding in 2005, but has dedicated his comeback to his "Livestrong" cancer prevention campaign.