Before Rocky Balboa pounded sides of beef in a South Philly meat locker, Sylvester Stallone was pumping iron in Berwyn.

“There is no Rocky without Philadelphia,” Mike Sielski declares in Going the Distance: Stallone, Philly and the Story of Rocky, his new book timed to the film’s 50th anniversary.

Rocky wouldn’t be Rocky without those runs through the Italian Market, those strolls through gritty Kensington, that triumphant climb up the Art Museum steps, argues the award-winning Philadelphia Inquirer sports columnist and WIP radio host in his fifth book.

But the Main Line looms large in Rocky’s origin story, too.