In 2012, Tom Hardy's metamorphosis into Gotham juggernaut Bane was the stuff of legend. The actor, who had previously rocked other demanding body changes for roles in Warrior and Bronson, had beefed up significantly to play Batman's arch-nemesis in the third instalment of Christopher Nolan's trilogy.

Almost 10 years later, Hardy's portrayal of Bane is still being talked about and, in a recent interview with BBC Radio 1, the actor shared the physical and mental toll the role had taken. In the latest episode of BBC Radio 1's 'Kids Ask' web series, a budding 10-year-old journalist asked Hardy about the prep required for the film — more specifically, how Hardy got "so muscly" in order to play Bane.

"If you really study the photographs [of Bane], I was really overweight, actually. I ate a lot and I wasn't much heavier than I am now, but I just ate more pizza. They shoot from low to make you look big," answered Hardy. "People would lift up the lids on their motorbike [helmets] and say 'I always thought you were bigger, mate'...I was just bald, slightly porky and with pencil arms."

Hardy as Bane in 2012’sThe Dark Knight Rises

"That's the magic of lighting and three or four months of lifting and training and eating lots of pizza. It wasn't great for my heart. The point was to look as big as possible," he continued. "I have really skinny legs and my friend Jacob Tomuri — my stunt man — liked to say 'Why did Tom come in riding an emu?"

To meet the demands of the role, Hardy — chameleonic as ever — gained two stone (13kg/30lbs) in weight, bringing him to a hefty 90 kilos. "Compared to Christian Bale I’ve been by no means extreme in my body changes," Hardy told The Daily Beast in a separate interview.

Hardy used a bulk-up "matrix" (check the moves out below) to build muscle on to his chest, arms and shoulders. Using a descending 'ladder' format, Hardy would hit a four-round circuit, going from 10 reps in the first round, to seven, to five, then to three. By utilising own body weight, he was able to wreak devastation on his body and pack-on muscle in a frighteningly short amount of time.

The Square: 10, 7, 5, 3 Reps

Position your palms so they’re ‘square’ with your shoulders. Keep your elbows tucked in, moving alongside your torso to detonate your triceps.

The Rectangle: 10, 7, 5, 3 Reps

Set your hands wide apart, so that when you lower your chest to the floor your arms, chest and the floor form a rectangle.

The Eagle: 10, 7, 5, 3 Reps

Start in the same position as above, but this time spread your fingers as you lower and turn them outwards. Take the pain.

The Kong: 10, 7, 5, 3 Reps

Assume a press-up position on your knuckles, your arms at shoulder-width. Lower your chest to the floor, letting your elbows bend back like a grasshopper’s legs. This is a final killer on your shoulders.

The Diamond: 10, 7, 5, 3 Reps

Place your thumbs and index fingers together in a diamond shape. Lower your chest to the centre of the diamond, then push back up again. Breathe raggedly.