Watch: Sandra & George Debut 'Gravity' in Venice


George Clooney and Sandra Bullock opened the Venice Film Festival with a bang today in Italy where the spiffy co-stars unveiled their brand-new sci-fi flick, Gravity.

Pics: Sandra Bullock with Baby Louis

The Alfonso Cuaron-directed (Harry Potter and the Prisoner of Azkaban, Children of Men) thriller, out October 4, centers around a pair of astronauts struggling to survive after a disaster in space leaves them tethered to each other and swirling into the blackness. For their roles, George (as astronaut Matt Kowalsky) and Sandra (as Dr. Ryan Stone) were expected to condition their bodies to an almost pro-athlete level of fitness. Only one star admitted to taking the requirement seriously.

"I just mostly drank my way into the job," laughed George at the film's press conference Wednesday. "[Sandra] had a trainer right there on the set and she worked very hard on it."

Video: Three Killer Clips from 'Gravity'

Not exactly a fan of traditional exercise at the gym, Sandra revealed her training secret lied within hour-long sessions of dancing by herself in her trailer.

"I just blast the music for an hour and don't stop moving my body," she said, adding that her strength-training routine consisted of constantly lifting her 40-pound son Louie, 3, who insisted upon being carried everywhere.