He played a mixed-martial arts fighter.
I also saw Tom Hardy in the British show The Take, where he played a thug.
I notice that when Hardy plays a brawler, he walks around in fight-or-flight. His head is tucked into his torso but jutting forward, and his whole body is tight and compressed. This is a great attitude to fight out of. If you walk around like this, you’ll likely want to fight too.
Many people get stuck in this position and it does them no favors. If you want to fight, then get into fight-or-flight (where the head juts forward, rotates back on to the spine, compressing and tightening the neck and the torso, the shoulders ride high). But most people would rather feel tranquil most of the time and they can’t because they’ve gotten stuck in some interfering tension patterns such as fight-or-flight. This is where Alexander Technique lessons can help.