The comedy pals have reunited for "Bad Boys for Life", the long-awaited third and final film in the buddy cop franchise, which began in 1995 and continued with the 2003 sequel, "Bad Boys II".
Smith, 51, initially wanted the duo to take on as much of the action work as possible, just like the old days, but it didn't take the stars long to admit they were no longer cut out for the physical toll of the stunt scenes.
"The big change for us (from previous films) was probably the amount of stunt work," Will shared in a joint interview on U.S. breakfast show "Good Morning America".
"When I started, I was like, 'We doing all the stunts, we doing everything, every one of these Bad Boys, 25 years later, all the stunts!' Then like, probably three days in, I looked over to (Lawrence), and was like, 'Hey, what you thinking?' "
"He was like, 'Yeah, we should probably let the stuntmen earn they money (sic)!' "
Lawrence, 54, acknowledges his larger frame is partly to blame for his lack of fitness, but jokes that packing on the pounds was all in preparation to reprise his role as veteran Miami Police Department Detective Marcus Burnett, who becomes a grandfather in the new film.
"I'm a lot heavier (compared to the previous instalments)," he said. "I put on a little more pounds (sic), but it's for the role...! Method acting!"
Smith, who plays his onscreen partner, Detective Mike Lowrey, quipped, "I was like, 'Oh, Martin's really into this character!' "
"Bad Boys for Life" opens in theatres next week.