Dwayne Johnson's personal strength and fitness coach Dave Rienzi says the Hollywood superstar never needs to take drastic measures or over-stress his body to obtain a certain look.

"We hold his conditioning in a very tight window to allow him to be ‘scene ready' at any moment. Keeping him at striking distance ensures that we never need to take drastic measures to obtain a certain look, or over-stress his body. The bottom line is that he always needs to be able to perform at his best on screen," said Rienzi, according to femalefirst.co.uk.

Johnson, who shot to fame as The Rock in the world of professional wrestling before cracking Hollywood, is also on a very strict diet, says his coach.

"The execution of his diet and training needs to be as nuanced and complimentary as possible to allow him to do that consistently," he said in an interview with Muscle & Fitness magazine.