While the Internet is split on director Zack Snyder's decision to cast Ben Affleck as Bruce Wayne in the "Superman vs. Batman" sequel, the move makes all kinds of sense when it comes to the actor's physical presence on screen. 

As detailed in my recent Superman vs. Batman workout and diet article, both superhero roles require actors who are willing to embrace the gym as their second home. For Henry Cavill, who played Superman in "Man of Steel," that meant almost a year of daily workout, intense eating regimens, and mental discipline to achieve what trainer Mark Twight and Warner Bros. were aiming for. 

Which is why Affleck is the perfect fit for this aspect of the Batman role. One only has to look at his physical transformation for the 2010 crime-thriller "The Town" (of which he also directed) for proof. 

"I was playing this guy who was supposed to be very tough, a professional hockey player, then he got into drugs and he quit and re-dedicated himself furiously to this workout regimen," he told Access Hollywood. "And I saw that and I didn't think about it too much - and then six months out I panicked and realized I have to transform my body, or I will be a complete fraud, and I will be derided openly, nakedly. I just didn't want to ask for all this reality from everyone else and not have it myself."

Affeck goes on to say that despite hitting the gym hard for the first three months, he still wasn't seeing the results he wanted. So he turned to former Boston Celtics strength and conditioning coach Walter Norton Jr . and famed trainer Gunnar Peterson for assistance. 

"It was horrible, horrible - but all worth it," the actor added. 

In what should be music to "Man of Steel" trainer Mark Twight's ears, who will likely lend his expertise once more for the sequel, Affleck remained focused and disciplined throughout his months of training for "The Town." 

“He not only has set aside time to train, he gets the proper rest and maintains a proper diet,” Walter Norton Jr. told the Boston Herald. “He does the things other people would struggle with on a daily basis and really excels.

“I’d like to take more credit,” he added. “But he’s pretty strict. He’s not a guy who comes up with excuses.”

Even actor Jon Hamm, who co-starred in the "The Town," took notice of Affleck's dedication to the task. 

“I think the discipline of having to work out and being focused on that as well as having to be prepared [as] a director, as well as having to be prepared as an actor — it was almost military in its structure,” Jon told Access Hollywood. “That was, I think, helpful to him and obviously the guy had to have a certain body type — pro-athlete. And all of that dovetailed nicely with looking good."

So rest easy, Internet. Ben Affleck may not have been your first choice, but let's not forget the uproar that followed after Heath Ledger was cast as the Joker. We may just find ourselves eating crow yet again. 

Related on MNN: What is the Tabata workout?

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.

Ben Affleck's Batman diet to mimic his 'Town' routine?
The surprise selection to star as the dark knight in Snyder's 'Superman vs. Batman' already has the experience to get in shape for the role.