EXCLUSIVE: Dunkirk‘s Aneurin Barnard and The Strain‘s Kevin Durand are boarding George Gallo’s bodybuilding-guru pic Bigger.

The pic follows the rags-to-riches tale of the grandfathers of the fitness movement, the Weider brothers. Barnard takes on the role of Ben Weider, brother to the iconic Joe Weider (Tyler Hoechlin), who was the brains of the fitness empire. Durand will portray the brother’s foreboding nemesis, fitness magazine publisher Bill Hauk.

Steve Lee Jones’ Bee Holder Productions is producing with Scott LaStaiti, Eric Weider of Weider Health is executive producing with Camila Castro. Bigger was written by Brad and Ellen Furman, Andy Weiss and Gallo. Production begins next month in Alabama.

Durand stars in FX’s The Strain, which ended its four-season run Sunday night. He also stars in the upcoming comedy horror Tragedy Girls opposite Brianna Hildebrand (Deadpool). His other credits include Fruitvale Station, X-Men Origins: Wolverine and 3:10 to Yuma.

Barnard also starred in the Weinstein Co. miniseries War & Peace and BBC’s Thirteen.

Barnard is repped by WME, the Artists Partnership and Felker Toczek Suddleson Abramson. Durand is repped by Alchemy Entertainment, ICM Partners and Bloom Hergott.