The Luther star took up the sport in order to get fit for his upcoming role as Nelson Mandela in Long Walk to Freedom.
He told New York Magazine: "If an alien craft were to come down and go, 'We want the fittest people in the world', we'd give them a bunch of soldiers and boxers. I want to take my body there."
Elba added that he is now considering making a documentary about his training and organising a boxing match to raise funds for children in Sierra Leone, his father's native country.
The 39-year-old actor also revealed that he isn't afraid of hurting his face, because he doesn't think of himself as an image-based actor.
"If I made my living off my face alone, I don't think I'd be here talking to you now," he said. "I don't have much to lose. Besides, there are characters out there that have crooked noses. I think I'll get those characters."
He currently stars in Ridley Scott's Prometheus alongside Noomi Rapace, Charlize Theron and Michael Fassbender.
Watch a clip from Prometheus below: