US astronaut finishes the first triathlon in space

Sunita Williams, a US astronaut aboard the International Space Station, completed the first triathlon in space Sunday.

Williams competed along with athletes in the Nautica Malibu Triathlon, which was held in southern California this past weekend.

She completed the nearly two-hour run, bike and swim, while orbiting 240 miles above Earth.

"I'm happy to be done," said Williams by videolink when she finished, according to CNN.

"It wasn't easy, and I'm sure everybody in California's very happy to be done too."

Her time? One hour, 48 minutes and 33 seconds.

She used exercise equipment that was put on board, including a stationary bike, a rowing machine and a treadmill in order to simulate what the athletes back on Earth were doing.

Exercise is mandatory for astronauts on board as zero-gravity environments are hard on the human body.

Sunita Williams is the commander of the crew of Expedition 33 on the International Space Station, whose mission began just a few days ago after a launch from Kazakhstan.

Williams is an avid athlete, according to the Christian Science Monitor, having already run the Boston marathon while in space in 2007.