Tom Hanks has started voicing Toy Story 4

Woody, voiced by Tom Hanks and Buzz, voiced by Tim Allen are back for a fourth Toy Story movie.

Tom Hanks has revealed he's already recording his lines for Toy Story 4 even though the film's scheduled release date is three years away.

"It takes a long time," Hanks told Graham Norton.

The 59-year-old said he gets a workout from voicing cowboy toy Woody.

"The recording sessions go on for four or five hours," said Hanks.

"By the time I'm leaving, I'm driving home and I literally have to put an ice chest on my diaphragm just so I can go home because it's clenched throughout."

Toy Story 4 is due for release in 2018.

- AAP