This dude is looking rockin'!
Jake Gyllenhaal is eager to prove that he's a serious actor and is ready for the big leagues like his fellow actor brethren.
And everyone knows that to be considered serious - you have to go through weight transformations like nobody's business!
Which is what Jake did when he got super skinny for Nightcrawler, and he happened to go the opposite way by getting extremely buff for his newest role in Southpaw.
The movie was written by Sons Of Anarchy creator Kurt Sutter and is directed by the dude who also helmed Training Day — Antoine Fuqua.
Here's what Fuqua had to say about Jake Gyllenhaal's transformation