Alexander Skarsgard: 'I wasn't good at swinging through trees'

Alexander Skarsgard didn't do very much of the rope work on the new live-action Tarzan film.

The Swedish actor, 39, admits that his early attempts "didn't look very good," so he was relegated to taking off and landing.

Alexander plays the King of the Jungle opposite The Wolf of Wall Street actress Margot Robbie's Jane in The Legend of Tarzan, and confesses that a very experienced trapeze artist had to come to his rescue.

The Legend of Tarzan, due for release later this year (16) and directed by David Yates of the Harry Potter film series, is based upon the fictional character created by Edgar Rice Burroughs.

"It didn't look very good... I'm not very good at that stuff," he laughed to E! Online at South by South West (SXSW), where he premiered his new movie War on Everyone, adding an expert with over 20 years experience did most of the "crazy stuff" in the $180 million film.

"I took off and did a little bit of it and then I sat in my chair with my coffee," Alexander generously shared. "He did the amazing stuff and then I came back and did the landing."

One area where Alexander did excel was in building the body of a man who lives off the land and runs in the jungle.

"I basically had him (a trainer) and a nutritionist. I've never done anything like this before, this extreme. I was just really nervous. It was a big challenge and I didn't know how my body would respond to the training and diet," he explained.

The actor needn't have worried though. Promo photos for the blockbuster show him looking extremely buff, a necessity as he appears shirtless in the film - a lot.

His routine for months prior to and during filming included eating "a lot of chicken cutlets (breasts)" and completing many "crunches (sit-ups)", with just the one cheat day. But by all accounts his cheat day was well worth the wait.

Alexander recalled his trainer taking him to lunch at an Italian restaurant in Notting Hill, London, and told him to order what he wanted.

"I started crying. He was like, 'Have pasta,' and I had it and then he was like, 'Are you still hungry?' I was like, 'Yeah!' He was like, 'Have a pizza then, have some tiramisu.' It was the best meal of my life," he grinned.

The Legend of Tarzan is out on 1 July (16).