The real space race

Nasa astronaut Sunita Williams finishes a triathlon while in orbit

Nasa astronaut Sunita Williams completed the first triathlon in space, running, biking and 'swimming' as, 250 miles below, athletes did the same at the Nautica Malibu Triathlon in Southern California.

After 'swimming' half a mile, biking for 18 miles and then running for four miles, Williams made an offworld-record of one hour, 48 minutes and 33 seconds - although these figures make no account of time zones.

The space station has a stationary bike and a treadmill, while harnesses and straps substitute for gravity and stop astronauts flying into the walls.

While there is not enough water to fill a swimming pool on-board, Williams used special weights on board to simulate the swimming section, which is a cross between weightlessness and resistance training.

Williams, the U.S. commander of the Expedition 33 crew, added: 'A big shout out to our astronaut strength and conditioning folks, who were really interested in this and who got this whole workout together.

'Thanks everybody for your support and ideas about health and fitness and how important it is for humans and getting us back into long-dura- tion spaceflight.'

NASA Mission Control replied: 'It's critically important to understand human physiology and how to keep you strong on orbit. Well done.'

All astronauts must work out regularly, or see their muscles and bones deteriorate in weightlessness.

And this is not her space- race: In 2007, she ran the Boston Marathon on the treadmill, in a time of four hours, 23 minutes and 10 seconds.