Armstrong to become Ironman

Armstrong to compete in an Ironman (Getty)

Once Lance Armstrong has finished his cycling comeback, his sporting career will turn full circle.

Armstrong has confirmed widely-held speculation that he will eventually compete in an Ironman triathlon.

As a teenager, the record seven-time Tour de France champion was a top-class triathlete over shorter courses in the late 1980s.

But he eventually switched to road cycling, where he has become one of the sport's greatest competitors.

"Whenever I'm done with this (comeback). I can unequivocally say  yes to that," Armstrong has told the American magazine Outside about entering an Ironman.

"That's a fact and I get asked that question every day. "I don't know when it was, less than a year ago, that I got some of these Ironman DVDs - I said 'let's see what that's all about'.

Typical of Armstrong, he also wants to be competitive when he attempts the gruelling Ironman distance.

An Ironman consists of a 3.8km swim, 180km cycle and 42.2km marathon run.

The winner finishes in around eight hours and the cut-off time for the late finishers is between 15-17 hours.

"I'm definitely motivated to do an Ironman," he said."We'll go back and I'll be close to 40, but I've swam more in the last three years than before that.

"And I don't want to just do an Ironman, I don't want to approach it like I approached the marathons, I want to do it as fast as I can."

In the three years since he retired from professional cycling, Armstrong competed in several marathons, posting a string of impressive sub-three hour finishes.

Armstrong also based himself on the Big Island of Hawaii for a post-Christmas training camp before flying to Adelaide last Sunday to launch his cycling comeback at the Tour Down Under.

While in Hawaii, he trained on the Queen K highway, the desolate stretch of road that is a key feature of triathlon's most famous race, the Hawaiian Ironman.