"I was surrounded by hundreds of stuntmen, who were amazing. Stuntmen are my favourite people on a film set, but I had this thing that really helped me get through, which was this thought in my head that, ‘If I can train in such a way that they’re actually going, “He is a badass…” – because I know stuntmen and they like actors but mostly they see them as wet blankets. [I wanted] to train in a way so they would actually take their hats off to me, and in a way so that you would believe that they would actually follow you. I was [working out] six hours a day: two hours with them, two hours doing the 300 work-out, two hours with my own bodybuilder… pumping 25 times before each take. But I was also surrounded by a lot of guys putting in a lot of effort. It was great having that unity of purpose both as an army and in terms of what we were trying to make in this movie and in terms of fitness, training and that warrior spirit. It was a very powerful place to be."