The film is the sequel to 1977′s "Pumping Iron."
Rourke, a former boxer, earned an Oscar nomination for his portrayal of a washed-up professional grappler in "The Wrestler."
"It made perfect sense," Yudin told RadarOnline.com about why he wanted to work with Rourke. "His voice is absolutely perfect for this. It has so much emotion."
Yudin said the actor's "very physical, very mental" persona, and the fact his father Phillip was a bodybuilder, made Rourke the ideal man for the job.
"The way he nailed the performance [in 'The Wrestler'] was amazing to me," he said. "'The Wrestler' was a very emotional film about an athlete who goes through ups-and-downs -- bodybuilding is not always the most rewarding sport."
"Generation Iron" is set for theatrical release Sept. 20.