ByMatt Kranis, writer at Creators.co
President of the Salacious Crumb Fan Club. Staff Writer at Movie Pilot. Twitter: @Matt_Kranis
Matt Kranis

Happy birthday, Sylvester Stallone! The action icon turns 70 years old today, and while he may be getting up there in age we have to doubt Sly can still keep up with the young guns of Hollywood.

Stallone's entertained five decades worth of moviegoers, bringing iconic characters like Rocky Balboa and John Rambo to the big screen year after year with huge success. And over that time, we've watched him grow from a small time actor to an A-list superstar.

Of course, we've also literally watched him grow from a lean actor to a buff action hero. He may be 70 years old, but Stallone's in remarkable shape — allowing him to star in demanding action roles despite his age. So, we're paying tribute to the actor's impressive physique with a comprehensive timeline charting the growth of Stallone's massive muscles.

The Party At Kitty And Stud's (1970)

Look at that studly Stallone.
Look at that studly Stallone.

It's only fitting that we start our body-centric timeline with Stallone's one and only softcore porno. Before he was a star, the actor agreed to take the lead role in The Party at Kitty and Stud's, naturally showing off plenty of his body.

We won't get into the X-rated stuff here — you can look that up for yourself — but this is clearly Stallone pre-action star. He's a fit guy for sure, but he doesn't have the body to head into the boxing ring just yet. Sadly, the actor can't live this one down — especially after the film was re-released following the success of Rocky under the title Italian Stallion.

The Lords Of Flatbush (1975)

Stallone with stars Henry Winkler and Perry King.
Stallone with stars Henry Winkler and Perry King.

Stallone snagged a number of bit parts in the early '70s, with one of his early starring roles coming in The Lords of Flatbush. The character seemed tailor-made for the star, casting him as a '50s greaser in Brooklyn.

Of course, the greaser role also meant Stallone's muscles were covered up by a leather jacket throughout much of the movie. But that's okay, because at this point in his career there still isn't that much to look at.

Rocky (1976)

Stallone in the boxing ring during "Rocky."
Stallone in the boxing ring during "Rocky."

It seems rather fitting that our first look at some proper Stallone muscles comes alongside the actor's breakout role.

Rocky found Sly enter the boxing ring as smalltime fighter Rocky Balboa, and the actor's dedication also saw him hit the gym for real to prep for the role. Stallone doesn't have the bulging muscles we'd see in later appearances, though he's clearly bulked up a bit, getting a believable boxer's body that lends plenty of credibility to the timeless underdog story.

First Blood (1982)

1982's First Blood signaled the start of Stallone's action movie domination, giving us another classic character in the form of Vietnam vet John Rambo. Thankfully the flick also saw an upgrade in those trademark muscles.

Stallone isn't that much bigger than he is in Rocky, but he's putting his chiseled physique to good use by taking out crooked cops and National Guardsmen with precision. Alongside the Rocky sequels, Rambo's '80s adventures seem to be a primary driver of Sylvester Stallone's muscle growth. He gets bigger with every sequel, proving that more of a good thing isn't so bad.

Over The Top (1987)

Over the Top definitely ranks as one of goofier entries in the Stallone canon, finding the star cast as a struggling truck driver who moonlights on the professional arm wrestling circuit.

The actor's bulging biceps take centerstage in this flick, though it's a little hard to believe he wins so many arm wrestling matches considering most of the brutes Stallone faces look even stronger. Once again, the underdog wins it all.

Cliffhanger (1993)

Stallone faced a small career slump in the back half of the '90s, but not before he starred in Cliffhanger. The action film literally took the actor and his muscles to new heights, following Stallone as a rescue ranger embroiled in a heist gone wrong in the peaks of the Rocky Mountains.

The film provided ample space for the star's strength to shine, with Stallone climbing cliffs, leaping across mountain ledges and generally being an absolute badass in one of the most dangerous landscapes in the country.

Rocky Balboa (2006)

After a slump in the late '90s and a brief hiatus in the early 2000s, Stallone returned to acting with Rocky Balboa. The movie was surprisingly good considering its status as the sixth Rocky film, but even more shocking was Stallone's physique.

The actor looked like he was in better shape than he was back in the '80s, rocking chiseled abs that would put Hollywood's young stars to shame. We assume he was hitting the gym all day, every day during that earlier hiatus.

The Expendables Franchise (2010 - Present)

Sylvester Stallone in "The Expendables 3."
Sylvester Stallone in "The Expendables 3."

With a reinvigorated career after Rocky Balboa, Stallone once again started featuring in the sorts of action films that made him famous. We even got another appearance from John Rambo in 2008's Rambo, but Stallone's physicality has truly shined in The Expendables franchise.

The star leads the good guy mercenary group as Barney Ross, and over the course of three films hasn't shied away from getting down and dirty despite his age. From one-on-one fistfights to epic shootouts and more, Stallone's fitness has allowed him to adjust to today's high octane action style with awesome results.

We love Sylvester Stallone's incredible muscles, but he's more than just a meathead action star. Remember, he's received three Academy Award nominations, including a Best Original Screenplay nom for writing Rocky. We love Stallone because he's a great performer, whether he's playing a bulked up action hero like The Expendable's Barney Ross or an ailing Rocky Balboa in Creed. He knows how to use his physicality to maximum effect, a hallmark of any great action hero. Luckily, Sylvester Stallone shows no signs of stopping anytime soon, meaning we'll get even more memorable roles from the Hollywood hero.

What's your favorite Sylvester Stallone movie? Let us know in the comments below.