“And then I had to be really secretive about Batman stuff.

Nolan, of course, famously put his own spin on Batman with theDark Knighttrilogy several years ago.

“The maximum workout I do most of the time is a casual stroll.

The Batman

Credit: Warner Bros. Pictures

John David can run all day long.

It was good that I ended up being pretty fit.

But definitely, at the beginning, there were days I just could not walk afterwards.”

(Remember what we said about Nolan’s secrecy?)

The film will open in select U.S. theaters on Sept. 3.