Tyler Hoechlin as Joe Weider

Aneurin Barnard as Ben Weider

Colton Haynes as Jack Lalanne

Julianne Hough as Betty Weider

DJ Qualls as Michael Steere

Victoria Justice as Kathy Weider

Kevin Durand as Bill Hauk

Steve Guttenberg as Louis Weider

Max Martini as Jerry George

Robert Forster as Joe Weider (2008)

Tom Arnold as Roy Hawkins

Calum Von Moger as Arnold Schwarzenegger

Jared Motyl as Steve Reeves

Nicole Weider as Becky

Diane Sorrentino as Kate

Christian Finlayson as Young Joe Weider

Miles Emmons as Ben Weider (age 7-9)

Nadine Lewington as Anna Weider

Sterling Hurst as Ivan Towne

Jason Burkey as John Corbine

Brian Brightman as Harry Crowne

Hunter Clowdus as Fitness Guy