Get out your star-spangled boxing shorts, and prepare to partake in an inspiring training montage. A documentary about the making of the Rocky franchise is making its way to digital on-demand on June 9. Virgil Films and Entertainment will be releasing the behind-the-scenes peek at the world of Rocky, with the star of the series Sylvester Stallone providing narration. 40 Years of Rocky: The Birth of a Classic is directed by Derek Wayne Johnson, who issued the following statement regarding the release.

"The documentary is a golden nugget for Rocky fans and casual audiences alike. It's a charming piece of film history narrated by Rocky himself, Sylvester Stallone, and will give audiences an intimate, and at times, emotional experience. We're proud of the film, and audiences can expect new stories and new footage that they've never seen before in a blend of director John Avildsen's home movies, rehearsal footage, and behind-the-scenes footage from the making of the ultimate underdog film."

The footage used in the documentary will be a mix of what audiences have seen before, and some new b-footage filmed by other creatives connected to the Rocky movies that has not yet seen the light of day, like makeup tests, boxing choreography sessions and other moments involving Stallone and co-stars Carl Weathers and Talia Shire.

While Rocky has come to be known as the ultimate underdog story, Stallone's struggle to get the film made was an even more impressive tale of battling against all odds. At the time, the actor was trying to break into the film industry. Discouraged with the roles that were being offered to him, Stallone set out to write his own script about a boxer who never quits no matter how much he gets beaten, based on famous boxers of the day like Rocky Marciano and Chuck Wepner, who famously battled Muhammad Ali for 15 rounds before getting knocked out.

Sylvester Stallone sold the script to United Artists studio on the condition that he would play the lead role. The film went on to become the highest grossing movie of the year, establishing Stallone as a leading man and spawning a still-running franchise.

The actor will be commenting on the various aspects of filming the series in his documentary narration, like the famous pork pie hat that he added to Rocky Balboa's wardrobe, which the studio was against until Stallone talked them around to it.

While Rocky's onscreen journey as a leading man ended with 2006's Rocky Balboa, the character continues to be a part of the original narrative with the spinoff series Creed. Here, Rocky plays the role of a mentor to Adonis, son of Rocky's one-time rival, and later close friend Apollo Creed. A third Creed movie is in the works, with Stallone hinting that he will be reprising his role in the film. In the meantime, fans can take a trip down memory lane with the Rocky documentary when it premiers on the 9th of June. This news originated at Deadline.