He looked pretty awesome as Vampire Eric in HBO's True Blood.

Now Alexander Skarsgard has shared how he bulked up even more to create a torso a pro-body builder would be proud of for his new film, The Legend Of Tarzan.

And it involved eating an astounding 7,000 calories a day to pack on 25lbs of pure muscle, he revealed in an interview with Mr Porter's Journal released on Friday.

A mass of rippling muscle: Alexander Skarsgard ate an amazing 7,000 calories a day to build his amazing body for The Legend Of Tarzan

To transform his naturally slender, 6ft 4ins frame into a muscle-packed powerhouse the 39-year-old Swede spent three months eating 'an insane' amount of calories - three times his usual intake - and lifting heavy weights.

Alexander changed the regime once he arrived in London to start filming, swapping to six smaller meals a day and completely cutting out sugar, gluten, wheat, dairy and alcohol.

He also had twice-daily training sessions to sculpt his amazing six-pack, awesome pecs and powerful guns.

Abs-solutely awesome: The 6ft 4ins 39-year-old Swedish star packed on 25lbs in pure muscle

Bringing in the big guns: Alexander, who appeared shirtless in much of the movie, co-stars with Margot Robbie as Jane

Warner Bros., the studio behind the Tarzan reboot, offered him one of its experts to help with the transformation.

But Alexander used his friend, Magnus Lygdbäck, a Swedish trainer and nutritionist he met when he was living in Los Angeles.

'When you have to see the same person every morning at 4:30 a.m., it’s important you get on well with them,' said the star, who now resides in Manhattan with his Brit model girlfriend, Alexa Chung.

Suited up: The star covered up his awesome body in a black two piece, matching tie and crisp white shirt while Margot opted for a black dress with Chinese-inspired patterns at the Tarzan Hollywood premiere on Tuesday

As Tarzan, Alexander spends most of the time topless, showing off his magnificent body.

But he was dressed in considerably more for the Hollywood premiere on Tuesday, donning a smart black suit and tie as he posed with Margot Robbie, who co-stars as Jane.

The Legend Of Tarzan, directed by David Yates, is released on Friday in the U.S. and July 8 in the U.K.