Fans were quick to comment on Williamson's photos, with many noting that Simmons was probably hitting the gym hard for his role as Commissioner Gordon in the upcoming fantasy film, Justice League, which also stars Amber Heard, Jason Momoa, Henry Cavill, Ben Affleck and Amy Adams.
Others joked that seeing these pics was enough motivation to start getting serious about their own diet and fitness plans.
"#Lifegoals, seriously man!" one user wrote. Another impressed fan commented, "I gotta get my sh*t together!"
Back in April, ET caught up with Simmons, where he admitted taking on the role as Commissioner Gordon felt "intimidating."
"You know, it's just another opportunity to see what I can do with a truly iconic character in that comic book world, which is a really fun place to go play," he said.
The legendary role was most recently played by Gary Oldman, and the 58-year-old actor couldn’t be happier with Simmons' casting. When ET chatted with Oldman at a press junket for Criminal, he revealed he was "absolutely happy" to hear about Simmons taking on the character.
"I hope he's fantastic in it," Oldman added. To hear more, watch the video below.