This picture taken on February 2010 shows Velib bicycles, a public bike rental service. In the CeBIT high-tech fair, bikes offer all the features fitness freaks have become accustomed to: for example, it charts the cyclist's heart rate, calories burned, distance travelled and so on.

Tiny beads of sweat break out on Konstantin Domorazki's brow as he races his bike through Beijing's Forbidden City pursued by a tenacious opponent he just can't shake off his tail.

Welcome to the exercise bike of the future. In reality, Domorazki is on a stationary cycle at Germany's CeBIT high-tech fair in front of a razor-sharp wall-sized 3D map display charting his course through Beijing.

The race over, he begins a more leisurely ramble. No opponent this time, just a gentle cycle over Sydney Harbour Bridge, the brilliantly-white Opera House gleaming in the sunshine to his left.

"Really, we can put him anywhere there are roads," said Paul Zernicke, a researcher at the Technical University of Berlin that is developing the project.

"Yesterday, we sent a Russian film crew through Moscow's Red Square and an Egyptian visitor to the Great Pyramids," he added.

"We have even programmed in the first stage of the Tour de France."

The bike offers all the features fitness freaks have become accustomed to: for example, it charts the cyclist's , calories burned, distance travelled and so on.

It also allows the user to track his progress by "racing" against himself using previous performances over a set route.

"For the Tour de France, we should have added a doping test," he quipped.

The bike enables a cyclist in, for example, Tokyo to "race" a friend based in Washington up the Champs Elysees in Paris.

In theory, there is no upper limit to the number of players who could take part in such a race, Zernicke said, although they have not experimented with more than six racing at a time.

The bike is still a research project for the moment, Zernicke added, although the technology could also be applied to treadmills for would-be marathon runners and be a feature of a gym near you within a few years.

As for Domorazki, the researcher exhibiting the bike, he has a long day in the saddle ahead of him.

"He's only just started," said Zernicke.

"But his colleague yesterday gave up at around 4:00 pm after cycling around 30 kilometres (19 miles)."

"I just can't take it any more," the shattered cyclist said, according to Zernicke.

(c) 2010 AFP