Angelina Jolie seems to have bags of energy for someone who is supposedly surviving on a liquid diet and suffering from exhaustion.

According to recent reports, on-set sources have voiced concerns that the actress is worn out and may not be up to the challenge of playing the physically-demanding role of agent-on-the-run Evelyn A. Salt in Salt, currently filming in and around New York.

But Angelina looked fighting fit and in good spirits on Sunday as she threw herself around on top of a lorry on Interstate 787 in Albany, New York State.

When she wasn't crawling about on all fours attached to safety wires, the Changeling star happily chatted to her stunt double and crew members.