By Kim Peiffer
Jul 31, 2015 @ 5:00 pm

Jake Gyllenhaal stopped at nothing short of lifting a 350-lb tire to wielding a giant sledgehammer to get into shape for his role as boxing champ Billy Hope for Southpaw. But how hard did he really work? I paid a visit to the L.A. gym where he trained to find out.

In the video above, trainer Terry Claybon takes me through one aspect of Jake’s many intense moves from his workouts—and yes, it involves a sledgehammer. Watch the clip above to see how it turns out.