So Ian Thorpe has performed the greatest tumble-turn of his career. Instead of freestyling off into a quiet retirement, he’s now decided on the about-face which will see him return to the fast lane, and probably a gig at the London Olympics next year.

It’s a recurring theme among sporting greats — from Muhammad Ali to Michael Jordan to Michael Schumacher — and while the reasons given for their comebacks all vary slightly, the underlying motivation remains the same: they’re competitors who get off on competing and (although they don’t say it in quite so many words) never really get used to a world where the adulation and applause has died down.

Still, if anyone can pull it off, it’s the Thorpedo, winner of five Olympic gold medals — the most by an Australian— and nine overall. And the man who, after Mark Spitz and before Michael Phelps, has worn the tag of “Best Ever”.

At his media conference yesterday, Thorpe, a champion freestyler in the 200 metres and 400 metres, said he would aim to contribute to the 100m and 200m relay teams, although his main focus will be on the 100m.

He revealed he made his decision to return last September, and ever since has gone to great lengths to keep his training in secret.

“I was really sneaky about the way I did my training. I’ve swum at eight different pools,” he said.

Thorpe said after visiting the Olympics aquatic centre in London he was amazed by the venue and knew he had to return.

“I could taste it,” he said.

The Sydneysider will train primarily in Abu Dhabi, away from the distraction of Australian fans and media, and remain in regular contact with head swimming coach Leigh Nugent. He said he was happy to be back and felt refreshed after an extended period away from the pool deck.

“I never though this would happen. I never thought that I’d be swimming in a competitive way again,” he said. “I’m very glad that I am. I’m glad I spent four years away from the pool. I needed those four years.”

It didn’t take long for Thorpe to cop flak for the way his return to the pool was revealed — at the press conference which was heavily branded by Virgin Blue and attended by hostesses who walked around the conference with microphones for journalists.

Thorpe said he was willing to accept the intense media scrutiny that will inevitably accompany his return, and denied the decision was motivated by commercial interests.

“The thing that is driving me is for me to be able to perform again,” he said.

Yet some in his sport have expressed reservations, questioning his motives and saying Thorpe had nothing to prove to anybody. The American great Mark Spitz was one such sceptic.

And the hero of the 1956 Olympics, Murray Rose, also said he was not so sure about Thorpe’s return at the age of 28.

“It’s like asking ‘does the Australian cricket team need Shane Warne?’ — the answer is obviously no,” four-time Olympic gold medallist Rose said.

“There is an ebb and flow in every sport. You can’t always be totally dominant. But if you look backwards then you are not developing your future talent as best as you can.”

But Thorpe doesn’t have to look far for inspiration. Butterfly specialist Geoff Huegill retired from swimming after the 2004 Olympics but announced his comeback in 2008 — and then went on to win gold in the 100m butterfly at the Delhi Commonwealth Games, in a personal best time.

Sportsmen in other endeavours have also tried and succeeded spectacularly. Kim Clijsters retired from tennis in 2007 to have a baby then, after two years, returned to the sport. Since then, she’s won three of her four Grand Slam titles, including last week’s Australian Open.

Michael Jordan returned to the Chicago Bulls — and helped them reach the playoffs — after two years of trying his luck in the minor baseball leagues.

Essendon champion Tim Watson retired from the AFL in 1991, was drafted by West Coast but then was coaxed back to Windy Hill by Kevin Sheedy in time to play in the 1993 premiership at age 32.

Jockeys Darren Beadman and Lester Piggott gave riding away — for quite different reasons; Beadman became a pastor, Piggott retired then became a jailbird — before returning to the saddle and achieving success.

So comebacks can work. But many backfire spectacularly.

We remember AFL goalkicking great Tony Lockett blundering around in his ill-advised and short-lived return with Sydney in 2002, after three years out of the game.

Bjorn Borg retired at the age of 26 in 1983 with 11 Grand Slam titles — and a peerless reputation — in his kitbag. But, for reasons best known to himself, the Swede tried to make a comeback in the early 1990s — with a wooden racquet — and failed miserably. Bad idea, Bjorn.

Seven-time Tour de France winner Lance Armstrong had a four-year break from pro cycling before returning in 2009, and never returned to the levels that made him such a revered figure in the sport.

Muhammad Ali retired from boxing in 1979 but chose to ignore all the warning signs and advice and came back to the ring in 1980, just to receive a flogging from Larry Holmes in what was to be his last fight.

And, most recently, Michael Schumacher quit Formula One in 2006 after winning the drivers’ championship an astonishing seven times. He then made an inglorious comeback last year, at the age of 41, for Mercedes GP in the 2010 F1 season when he had to get used to finishing mid-field race after race.

And the list goes on. And on.

So best of British for your Olympic comeback, Thorpey. On all the evidence, you may well need it.

*Back Page Lead is a sports opinion website that provides sports content to Crikey.